@nsmith said in Control PWM hardware from C: I notice that for GPIO 20 and 21 it has the same command above, is that correct? Yes, the muxing of GPIOs 20 and 21 is controlled by a single command. These pins can be regular GPIOs, serial UART2, or PWM channels. They're controlled together since UARTs are always 2 pins. Because of this, you'll only need to run omega2-ctrl gpiomux set uart2 pwm23 once and both GPIO 20 and 21 will be set to PWM.

@Lazar-Demin it works perfectly

Cool project!

Thanks for the detailed explanation! Though it makes me wonder why GPIO11 is on the breakout header at all. It doesn't seem usable by end users.

@manuel-vera Just ran the same test on PowerDock2, same result. Are you using Powerdock or Powerdock2? Looks like PowerDock. I don't have this to test.

@Matt-Gessner-0 See the Omega2 Pro guide here: https://onion.io/omega2-pro-get-started/

I was trying to avoid to use the Arduino dock (that I have) Maybe the ADC expansion is the only option. Thanks for the reply

nice job. thanks for sharing.

Definitely doable to run vanilla LEDE or OpenWRT on the Omega2. We've upstreamed the Omega2 device to the LEDE project. Happy hacking!

@Arun-Soman What you have there is the command line tool for PWM expansion. For python program you need to use python library instead. check the following document https://docs.onion.io/omega2-docs/pwm-expansion-python-module.html

@Marti-MG I hope I'm not too late. If you want to use GPIO18 (PWM_CH0) only then you should remove U6 the 6 pin SOT23 marking C145 SMD IC only. See also the official Omega-Power-Dock schematic. After this modification Power Dock 1 remains fully functioning. You can check the battery level visually with the pover-dock command as before - but the 'battery level check' scripts will not work of course. Power Dock Checking the Battery Level

@ccs-hello said in PWM board related: OP is talking about driving motor(s), not LED Yes. Please notice only OP wants to connect a motor to the PWM Expansion - not me. (sink 25 mA max per channel.) 400 mA in all! It's not bad for this degraded "signalling-only" board. What motor can be driven only using 25 mA? Who knows? I'd be curious too. See also the first paragraph of PWM Expansion Back EMF, stall current, etc.??? Motor driver board is the way. flywheel diode, snubber, no-load current, ... A logic level n-channel MOSFET (or an NPN transistor) and a 1N400x diode are not enough - all we need is motor driver board!

[SOLVED] I found out the servo is discontinued. I think it has flaws in its design. I can't explain why it sort of works (only one direction) from the USB thing and does not from the expansion board, but I got 2 different newer winch servos and they work great in both directions from Onion and my USB thing, so it has to be a faulty servo. I have a feeling it had a 1 to 3 turn limit before breaking a cog if it driven past that, then once the cog is broken the pot doesn't return the right values and its all screwed up. Anyway the expansion board seems pretty bullet proof for noise and EMI EMF, I man handled it pretty good.

here is a basic idea on how i would like it to operate. I will make the actual models on the weekend. Its basically like your board, the only difference is the daisy chain, and the there is only 1 power input. The omega will receive power from the servo board.

@Lazar-Demin I'm really glad about the open source LEDE tree! Thanks! As I am just on my way to vacation right now, I can't dig deep into it right now But regarding PWM, the only thing that seems missing (I couldn't actually test, just compared my tree / .config with yours) is actually enabling it in the device tree. I had to append &pwm { status = "okay"; }; at the end of target/linux/ramips/dts/OMEGA2.dtsi to make the /sys/class/pwm interface work for me with kernel 4.4 (lede-17.01), so it should work for the Onion FW build. With kernel 4.9 however, (LEDE master) there seems to be some resource conflict over GPIO18 and 19, which makes the PWM driver fail at load. Couldn't find out details yet.

I did this: PWM0_SEND_DATA0 <- 0xAAAAAAAA (1010101010101....) PWM0_SEND_DATA1 <- 0xAAAAAAAA (1010101010101....) Clock 100kHz/2 - 50kHz And for 1% duty (for example): PWM0_HDURATION <- 500 PWM0_LDURATION <- 50000-PWM0_HDURATION It works. I have exactly 10ms step regulation. My rectification column power regulator is much closer Thanx!