Let's roll up our sleeves and do some detective work!
1. Test your BBC micro bit
Lets first make sure your micro bit works with both the USB and battery pack.
- Flash your micro bit with the attached (at the bottom of the article) microbit-heart.hex file
- Does it display a heart? If yes, it's working. Hooray!
- Remove the USB cable
- Plug in the battery pack. Make sure the 2 AAA batteries have charge. Does it still display the heart?
- Working? Great, let's move on. No? Please get in touch here
2. Check the wiring
Compare your micro bot with that on Club Make -- make sure they're matching. Check each component is connected correctly and as securely as possible.
3. Flash your micro bot code
- Flash your micro bit with the file microbit-Micro-bot-Test.hex below
- Unplug the USB, plug in the battery and reattach it to your bot
- Green croc clip to Pin 0
- Yellow croc clip to Pin 1
- Black croc clip to GND
4. Test the Battery pack, Servos and Wagos
- Make sure the 4 AA batteries are fully charged. If in doubt, try some new ones.
- Switch off the battery pack then switch it on again, both the servos should do a little jump.
- If they don't then there is a problem with the power circuit connections
- If they do jump then the issue is with the control signals from the micro:bit
If the servos don't jump:
The issue could be with the wago connections, the servos themselves or the battery pack. The most likely reason is the wago connections.
To test this - unplug all wago connections - connect 1 servo straight to the battery pack with jumper wired and croc clips (red to red, brown to black)
- Repeat the switching battery pack on and off and see if it jumps. Do this for both.
- If this doesn't work (and the batteries are full) then there is an issue with battery pack or servos and it will need replacing.
- If this does work, try stripping off some of the plastic coating on the battery wires so there is more connection. Make sure that the Wago's are completely open when inserting (this can be difficult but they should be 90degrees out) and completely shut when finished.
If they do jump:
Then there is a problem with the micro:bit connections
The micro:bit batteries are low, test this by trying to run the bot on usb power.
This code isn't flashing properly, test this by flashing the attached hex file.
The wire connections are loose, test this by making sure the croc clips aren't touching, and they are clipped onto the pins properly.
Still no joy? Please follow the step here for getting in touch.