Alisha AM4 Attiny 85 troubles

[pseudo sundial]

Hey all, I am just started working with Crashworks boards, and having an issue with one of mine, and wanted to see if anyone else has had this issue or has any ideas to fix.

I have 2 of the boards, so opened up one of them, and got everything hooked up, just for testing to make sure all was working good before I started permanently putting things in place. All was going good, then all of a sudden the board seemingly has stopped working. The light comes on, so it is getting power. But the switch does nothing. I've tried other switches, and even just tapping the wires together with no luck. Just nothing happens now.

I hooked up the second board, and it works fine. So should I try re installing the code on the one not working? Or do you think there is a hardware issue. Nothin visible indicates anything wrong with it though.

[stray wagon]

Hey @pseudo sundial, thank you for contributing to this forum.
Please provide as much information (images, video, description) as you can. This will increase the chance that someone can help you with your issue.
Use the Close button when your issue is resolved.

[dense scarab]

A few questions to get started:

• What are you powering the board with ?

• What type of switch did you use ?

• Can you share a picture of how the board is wired ?

[pseudo sundial]

powering with a 5V usb power bank. I was using a limit switch and it was working fine, then stopped. I switched out the limit switch to another with no luck, then eventually just tried tapping the bare wires together without a switch and nothing.

[pseudo sundial]

I'm not able to take a picture right now, but I have the power bank into the power plug. Switch into the blue switch plug, and servo's into their plug. But also though the red light come on once power is plugged in, it also doesn;t due the start up my other board does, without pushing a switch or anything. Just nothing happens now.

[tawny jolt]

What amperage is your power supply. How is your switch wired? It should be NO + COM

Is it a “smart” power supply?

[pseudo sundial]

Power suplpy is 5v/1a. It is dumb one power supply, doesn't go into a stanby or sleep mode.

Like I said, the second Alisha board works fine. And even the first one did work fine for a few cycles, then stopped

[tawny jolt]

Well 1amp isn’t typically enough power to operate the servos/LEDs & board. Maybe with zero load they will spin but 2.1amp minimum is recommended.

You should take some photos and a video of what’s happening. It helps to see what’s going on

How’s your switch wired

[pseudo sundial]

Switch is wired com and normally open (NO).

The power bank works fine with the other Alisha board,. Also with past helmets I made where everything was just set up analog.

[dense scarab]

With digital electronics , Arduino , ATTiny, etc... The Current is an important factor. 1A may work under non-loaded conditions, but the processors are delicate and can be damaged over-time being operated in an "under-powered" state.

If you continue to use the 5v (1A) with the current board that works, you may find , over time it will fail.

Also , when setting up a circuit in an "Analog" condition, the requirements are different. Since there is no Micro-controller (processor) involved. The 2 scenarios of "Digital" setup (with board) and "Analog" are not the same, and can't be compared this way.

According the MG90s Servo spec sheet, each MG90s when moving a load (weight) typical draws approximately 700mA (.7A) but this can spike to 1000mA (1A). So , in a typical Iron Man helmet with 2 servos this would be at a minimum 1400mA (1.4) without including the LED eyes or Control Board (AM4), which is why a USB power bank rated at 5V (2.1A) minimum is required. See the attached MG90s Specs:

With no weight attached, and the servos just sitting on a bench, you can get away with less current. Per the chart typical movement current is 250mA (.25A) per servo not under load (Weight), so for 2 servos it would be 500mA (.5A). So for testing on a bench the 5v (1A) power supply may work, but that means that with the servos drawing .5A from the power bank, that only leaves .5A (500mA) for the AM4 Board and the LED eyes, which creates an "under-powered" problem.

[pseudo sundial]

So I got another power bank, 5v/3a. Still second board works, and first doesn't.

Also as a FYI when I said it was working, it was with the facemask on and everything, not just the servos on their own

[dense scarab]

Understood, but as mentioned above, by running the board with only 1a (1000mA) it was under powered and failed over time (a few cycles).

The first board probably lost it's boot-loader (Program). If it's not damage, the code can be re-uploaded to the board, this is something you can try. However, if the Processor is damaged, the bootloader would need to be re-installed, which you may not be able to do unless you have the right equipment.

If you want to try to re-install the code to the board, here is some info and the files you will need:

https://github.com/crashworks3d/Iron_Man_Servo_AM

[pseudo sundial]

So I have started going down that road, and in IDE got the script in, installed the pre prerequisites, but then still get a whole bunch of errors. Mainly around Adafruit Softservo

I should say when I do the verify. I have not uploaded it to the board itself