To test this feature, visit your live site.

Voltage Issue

Hi All,

I modified the CNC shield as described for the Silent Clock but when I tested the circuit with a stepper motor nothing happened. I had fried the Nano. Checking the CNC shield with a volt meter I had 12 volts on all the points where I should have had 5 volts. Looking at the two pictures can anyone see anything obvious I had done wrong before I buy 2 more boards and make the same mistake.

Thanks for any help.

Steve.

3 comments

3 Comments

Steve

The wiring edits look good.

One reason for using the TMC2208 is that it can run on a 5V power supply. Normally, the CNC Shield V4 runs using an 8-12V power supply provided through the large barrel jack with 5V for the Arduino Nano getting produced by the onboard voltage regulator. However, we want to simplify the power delivery by using 5V from the USB cable. The USB cable plugged into the Arduino Nano is the only power connection to be used.

My first question is: Where did the 12V come from? I don't know if the onboard voltage regulators are simple regulators or if they can boost the voltage. Some high power USB power adapters can provide voltages higher than 5V, but only if both sides negotiate for it. There is no reason to expect the Arduino Nano to ask the USB adapter for more than 5V. I wonder if your USB power adapter is faulty.

Unfortunately, all the components that had 12V applied might have been damaged. I suggest starting with small steps when you start again. The first step should be with just the Arduino Nano plugged into the computer to program it. The algorithm will still run and show results on the serial debug monitor. It won't find the RTC, but it will still try to send pulses to the TMC2208. Add components one by one after this. I do this while still plugged into the computer USB port.

Once you know the Arduino Nano is programmed, you can use an external USB power adapter for the next steps. I recommend using a different adapter just in case. The clock uses less than 100mA so any USB power adapter should work. Start with just the programmed Arduino Nano plugged into the CNC Shield V4 using a simple USB power cable. Test some of the debug modes using the programmable jumpers. You should be able to get the LED to blink. Then, plug in the RTC and check the RTC debug test. The LED should be on for 1 second and off for 1 second if the RTC was recognized. Plug in the TMC2208 and stepper motor as the final step.

Hope this helps. Good luck next time.

Steve

Replying to

At least you have an explanation so the same thing doesn't happen again. Removing the jumper labeled Mot_VOT_Sel will disconnect the barrel plug to make it even less likely to happen.

I will add a comment in the assembly guide to try to prevent the same issue from happening to others. I am currently refreshing all the older designs with the newest design styles. SP2 and SP3 are getting a major overhaul with an "easy build" frame and the simple printed pendulum arm. Most of the other clocks will get smaller updates.