[beagleboard] Re: PWM: only a finite number of pulses? Controlling stepper motor
May be you can ask these guys here: http://www.halaser.eu/e1701m.php They're offering an industrial motor controller based on an BBB and should have solved this problem. Am Samstag, 18. Oktober 2014 03:26:26 UTC+2 schrieb plla...@gmail.com: http://electronics.stackexchange.com/questions/134356/beaglebone-generate-finite-pulse-train# I'm wanting to use the BeagleBone Black to generate a FINITE number of pulses, in order to control a stepper motor. For the controller I have, an A4988, each pulse is one step on the motor. How can I use the PWM on the BBB to send, say, 5 pulses, and no more or less than 5? Or I can use a GPIO. Whichever works. I have the Adafruit BBIO library https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/using-the-bbio-library installed. I have thought of doing this in a simple, stupid way - just using python's time.wait() and toggling a GPIO pin, however many times I'd like. But this seems very inaccurate, timing-wise, and moreover inelegant; is there a way to do this better? I'm also investigating events -- i.e., count the numberof pulses that have occured using another GPIO, then stop the PWM when the number of pulses I want has been counted. Any ideas? -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Re: starterware emmc beaglebone black
Starterware does not support access to eMMC. To do that, you would have to implement MMC-support to their HSMMCSD-library in order to make MLO able to boot APPs from there. Am Donnerstag, 16. Oktober 2014 22:28:31 UTC+2 schrieb TheMdv18: Hi everybody, My question is, I can boot starterware examples in flash EMMC (MLO+app), I did this in uSD card, but want to use the USB or Serial to flash EMMC and boot my application. There is anyway to do this ? Thanks in advance. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] LCD-cape with Ubuntu?
Hi, there are some LCD-capes available out there for BBB, mainly with very vew documentation. So I'll ask this here: which of them is supported by Ubuntu? Thanks! Karl -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Re: reset beaglebone
What ever causes this (changed) behaviour can be found on your on-board eMMC. There something seems to have changed with the bootloader which now lets the BBB boot from external SD card first. May be you installed Ubuntu? AFAIK this modifies bootloader in this way. Am Dienstag, 7. Oktober 2014 07:41:35 UTC+2 schrieb Olga Esquiroz: Is there any way to reset the board? That is, when I insert a SD I want to press the button user. Right now, when I insert an SD, the board boots from the micro SD without pressing the button. I want to reverse this. thanks -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Re: What is smallest period for PWM?
EHRPWM functions of AM3358 are running with 100 MHz. Thus the smallest possible half pulse width is 10 nsec (10 nsec of and 10 nsec on for a full period). Am Sonntag, 5. Oktober 2014 00:53:06 UTC+2 schrieb Bill Gray: So, I've been playing around with PWM, and I would like to have one PWM channel drive a buck circuit and another channel drive a boost circuit. The magnetics that I am looking to use would like to be driven in the 100-150khz range. Mosfets to drive this are not a dime a dozen, but perhaps $10/dozen. I've read other places that the PWMs can have a base frequency as high as 1.6Mhz? Currently I'm using P9_14 to drive the input of an oscilloscope which is 1Mohm-15pf and the wave form looks like slow capacitor charging. When I model the slope on spice it looks like the output impedance of P9_14 might be in the 50-70kOhm range? This means that I can't create a crisp pwm signal at any where near the frequency I'm hoping for. Also, this would mean that the maximum current out of a pin at 3.3v would be 0.06mA... and that has got to be wrong as I have seen too many warnings to limit source/sink current to 6mA or less??? Any ideas what I might be doing wrong that is limiting my pwm max frequency so badly? Thanks, Bill -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Board shipments decreasing
Hi, according to http://elinux.org/Beagleboard:BeagleBoneBlack#Board_Shipments board shipments are decresing constantly for some months. What is the reason for this? When I have a look to distributors of hardware they are still not available without longer delay, so what is going on here? -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Re: Bluesteel basic option for flash?
I got mine meanwhile, for my application it fits perfectly (don't need on-board MMC and HDMI). Finish looks good and it is working first few hours properly. So it seems to be a great piece of hardware. One thing to note: comparing to the original BBB it comes without Micro-USB-cable but within a very stable steel-case. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [beagleboard] Why use C/C++ file I/O to access GPIO pins?
Am Dienstag, 19. August 2014 04:40:43 UTC+2 schrieb john3909: Well, that is because you are trying to access the GPIO from user space. If you wanted to access the GPIO from kernel space, you would use a similar approach to what you did on your smaller processors. The only difference would be that each pin supports several functions which are defined by Mode 0 through 7. To use a pin for GPIO, you would use Mode 7. Also, the processor has a set register and a clear register so that you don’t have to disable interrupts during a real/modify/write. One other approach is to use mmap so that you can access the processor registers in user space for GPIO operations or as others have proposed, use the PRU to control GPIO. An other approach would be to drop Linux OS completely and to have your own (StarterWare-based) firmware running on the board. With it's standard timers you can have a output frequency of up to 2 MHz (when doing it out of an ISR with some bit-banging code) or up to 100 MHz (when bit-banging using PRU-code). -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Re: REV-C: Ethernet not working if Orange/Yellow LED is not blinking immediately after power-on
I found a posting at TIs webbord regarding this problem. There a guy from TI described this as a bug in used PHY. Since the RESET-input of that PHY is not connected to a (switchable) output pin on the BBB, only power of/on helps to workaround this problem. With such a connection a software workaround would have been possible where the PHY is resetted by Ethernet-driver until it reacts as expected. Am Montag, 18. August 2014 14:42:14 UTC+2 schrieb BB-RevC: Good day, I have several *Beaglebone Black Rev C*. They are connected to my LAN by using a static IP address. I observed that from time to time connecting to the Beaglebone Black via ethernet is not possible. *I identified the following behavior:* The ethernet port has two LEDs, a Green one and an Orange/Yellow one. If I apply power to the Beaglebone Black I noticed that the green LED immediately starts to blink. However, the yellow LED stays very often dark. *It simply never blinks during the whole boot process of the board*. In this case ethernet will not be available after booting linux and the board can not be reached via ethernet. *My workaround:* https://lh4.googleusercontent.com/-ccszPy8rMis/U_Hz2KG6ngI/ACM/mfEH9GBYDzE/s1600/bb_ethernet.png Is this a known respectively a bug? I observed this with several Beaglebone Black Rev-C from Element 14. I also have 2 Rev-B boards and I think (currently not 100% sure since these boards are not used at the moment) that I observed the same behavior. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Re: USB ports swapped, USB0 will not enumerate
Sure this is a hardware-problem and not caused by the software on your board which is accessing the new/other USB port in a wrong way? Did your firmware ever work properly with the original BBB-hardware? Am Mittwoch, 13. August 2014 21:33:27 UTC+2 schrieb Brendan Bleker: Hello, I have a custom board based on the Beaglebone Black, I'm trying to get the board to boot from USB, with nothing programmed on or SD card. I'm expecting to get the AM335 RNDIS to initiate as an Ethernet device. On our board (compared to the Beaglebone Black), we're using USB0 with the OTG circuitry (instead of USB1) and forcing USB0 into device mode. The board is detected by the Linux PC, however, It will not enumerate. The following is the dmesg I was able to get (running Ubuntu 12.04): [424595.900132] usb 5-2: new full-speed USB device number 4 using uhci_hcd [424596.075024] usb 5-2: unable to read config index 0 descriptor/all [424596.075032] usb 5-2: can't read configurations, error -71 [424596.188220] usb 5-2: new full-speed USB device number 5 using uhci_hcd [424596.251145] usb 5-2: unable to read config index 0 descriptor/all [424596.251158] usb 5-2: can't read configurations, error -71 [424596.364184] usb 5-2: new full-speed USB device number 6 using uhci_hcd [424596.422150] usb 5-2: unable to read config index 0 descriptor/all [424596.422164] usb 5-2: can't read configurations, error -71 [424596.423023] hub 5-0:1.0: unable to enumerate USB device on port 2 The board hardware has been modified slightly from the Beaglebone Black. First, we are using a type A usb connector, second, USB0 is now connected to the (USB1) OTG hardware, with USB0_ID pin floating (no access to USB1). Are there any other modifications to hardware required to get this working? Thanks -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [beagleboard] Re: Write to EEPROM on BBB?
Am Donnerstag, 7. August 2014 17:00:03 UTC+2 schrieb Gerald: Make sure you remove the write protect that is on the EEPROM Is there any other write-protection than the WP-pin of the chip that has t obe pulled to LOW? -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [beagleboard] Re: Write to EEPROM on BBB?
Am Mittwoch, 30. Juli 2014 11:14:05 UTC+2 schrieb lisarden: Write Protect pin is LOW-Active. This means that by grounding this pin you do memory protection https://www.facebook.com/mentorel.company Sure? EEPROM documentation says, write-protection is disabled when WP-input is pulled to Vss. On BBB, Vss is ground so pulling WP to ground should do the trick. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [beagleboard] Re: Maximum current on GPIO?
Am Dienstag, 29. Juli 2014 20:52:22 UTC+2 schrieb Brandon I: sink 8mA So setting a GPI to HIGH just by connecting it to 3.3V directly would be a problem? I assumed GPIO-inputs are always high-resistance!? -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [beagleboard] Re: Maximum current on GPIO?
This doesn't answers my question. So to describe it more clear: - board/CPU is powered and running - SYS_RESETn is HIGH - GPIO is configured as input ...so all preconditions mentioned in BBB manual are met. Now when I want to set a HIGH signal to that GPI, can I connect it with BBBs 3.3V directly or is a resistor needed in order to keep this 8 mA sink limit? Am Mittwoch, 30. Juli 2014 12:52:08 UTC+2 schrieb PLyttle: BeagleBone Black System Reference Manual Rev C page 113| (in bright red font): There are several precautions that need to me taken when working with the expansion headers to prevent damage to the board. 1) Do not apply any voltages to any I/O pins when the board is not powered on. 2) Do not drive any external signals into the I/O pins until after the VDD_3V3B rail is up. 3) Do not apply any voltages that are generated from external sources. 4) If voltages are generated from the VDD_5V signal, those supplies must not become active until after the VDD_3V3B rail is up. 5) If you are applying signals from other boards into the expansion headers, make sure you power the board up after you power up the BeagleBone Black or make the connections after power is applied on both boards. Powering the processor via its I/O pins can cause damage to the processor. Those kind of assumptions might kill your board. LP On Wednesday, July 30, 2014 12:38:31 PM UTC+2, karlka...@gmail.com wrote: Am Dienstag, 29. Juli 2014 20:52:22 UTC+2 schrieb Brandon I: sink 8mA So setting a GPI to HIGH just by connecting it to 3.3V directly would be a problem? I assumed GPIO-inputs are always high-resistance!? -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Write to EEPROM on BBB?
Hi, I try to write some data to EEPROM of BBB out of own (bare-metal) software. Reading data works fine and code for writing should be OK too, unfortunately data are sent to EEPROM but not written. From schematic I found EEPROMs WP-input has to be pulled to Vss so I connected TP4 of BBB with ground (pins 1/2 of P9). Unfortunately this also did not help. So...anything else that could be missing? Thanks! -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [beagleboard] Bluesteel basic option for flash?
And who is responsible for the BlueSteel? http://elinux.org/CircuitCo:BlueSteel-Basic mentions CircuitCo as vendor... Am Montag, 30. Juni 2014 14:27:29 UTC+2 schrieb Gerald: You need to ask the BlueSteal people. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] LEDs flashing but board is not booting
Hi, I have a problem with an own, custom cape. When the cape is not connected, the BBB boots well. When my cape is connected all four user LEDs are flashing with a delay of about 1 sec but the board doesn't boot. My cape already does take care about SYS_RESETn signal, I do not drive any (HIGH) signal into BBBs pins as long as SYS_RESETn is not HIGH. So...what could it mean when all these LEDs are flashing? Thanks! -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Colour depth of display on Mini Display Cape?
Hi, I'm just checking out the Mini Display Cape and the documentation of used CrystalFontz display. It seems all parameters are already set, at least I could not find a possibility to set EXTC pin in order to write some own system function commands to display controller. So my question: what is the predefined configuration of the display controller? And especially which colour depth is configured? RGB 4-4-4 or something different? Cheers Karl -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] Toggle power via software?
Hi, is there a possibility to have a really hard reset via software, e.g. by toggling the power? I hoped TPS65217C is able to do something like this but I could not find a functionality that gives the possibility to power of the CPU for a short time only. So...are there any other solutions to have a really cold reboot? Cheers! Karl -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [beagleboard] Re: PRU FAQ 2013-05-15
Am Mittwoch, 2. Oktober 2013 22:03:29 UTC+2 schrieb Charles Steinkuehler: Each PRU has it's own r30, which drives the direct outputs (assuming you have the pinmux setup properly). You can only drive a limited number of the BeagleBone header pins using PRU direct I/O, and a lot of the pins are shared with the LCD/HDMI interface. I afraid this is the part I didn't understand with PRU. Assumed Pin-Mux is correct for usage of plain GPIOs - is PRU able to access all of them? If not: which ones are accessible? And I already stumbled upon this r30 thingy...how can I set/read GPIOs with it? Thanks for helping me with these stupid questions! -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[beagleboard] P9 Expansion Header question
Hi, at http://elinux.org/Beagleboard:Cape_Expansion_Headers#Full_Headers_with_8_Modes the pinout of expansion headers is shown. For every pin there is exactly one row describing the functionality of the related pin according to a chosen mode. But pins 41 and 42 of header P9 are different, they are named 41# and 42@ and contain two rows describing possible functionalities and two GPIOs each. So...what does this mean? How can one choose a specific functionality of these pins? Setting the pin-mux-mode doesn't seem to do the trick since it can be used with the standard modes only and here twice as much are listed. Karl -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups BeagleBoard group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
