Wixel + Maestro + MinIMU-9

Hi, guys!
I’m a developer, newbie on eletronics, so please dont mind with my dumb questions…
Im trying to connect these little toys: A pair of wixels, a mini Maestro (12ch) and a MinIMU-9 (gyro, accelerometer and compass).

In first scenario, i did connect the wixel TX directly to the maestro RX, write the Wireless Serial App to both wixels and played a bit on virtual com, sucessfully.

Now, i want to add the MinIMU-9. What approach should i do?
I thought on use the “Serial-to-I²C App” on the Maestro side, but then, how can i connect the maestro to the wixel?

I also thought about the daise-chain, but i dont know how to do, what to connect or even if it is possible.
Also already thought on connecting the MinIMU-9 to one analog input of maestro, but later find out that it’s nonsense.

What can i do?
Do i need to alter the “Serial-to-I²C App” to accomplish that?

Thanks a lot!

I took a look on the serial_i2c.c file.
I think that this will be the easier way.

On “BRIDGE_MODE_RADIO_I2C” mode, it doesnt starts the UART. I was thinking on changing that, adding the uart1Init(); and the uart functions to act as i wish.

On the “parseCmd” method, it have a case with “CMD_GET_ERRORS”, “CMD_START”, “CMD_STOP” and the default “ERR_CMD_INVALID”. I was thinking on adding the “0xAA” from Pololu Protocol, and redirect it to the uart, to send the commands to the Maestro.

This probably can do the job, right?
Am i missing something?

See that the point here is to make a PC+Wixel take full control and comunication with a Wixel+MiniMaestro+MinIU-9. I dont want to use an Arduino, i wanna control everything from a pc, with feedbacks plotted on screen, like a control center.

Thanks a lot!


The easiest thing to do is probably to just get another pair of Wixels to establish a wireless communication link between the PC and MinIMU-9, which would be totally separate from the wireless link between the PC and the Maestro.

If you want to make things work with just one Wixel pair, then you will have to heavily modify one of our Wixel apps. Using the serial_i2c app as a starting point is a good idea. It sounds like you want some way to demultiplex bytes coming from the radio, having some of them be interpreted as I2C commands and some be interpreted as Mini Maestro commands. I think what I would do is make a new command in parseCmd called CMD_SEND_4_UART_BYTES that tells the Wixel that the next 4 bytes received from the radio should be sent to the UART. Then on the PC side, you just send CMD_SEND_4_UART_BYTES, followed by a 4-byte Maestro Set Target command. Does this make sense?


Thanks for your answer, David!
It SUPER makes sense! It’s exactly what i’m trying to do, but i think i’ll try to be more general with the Pololu Protocol and try to route many commands from the protocol, not only the setTarget one.

Once i already know the connections i can try (level-shifting TX/RX from wixel to maestro and SCL/SDA from wixel to MinIU-9, all GNDs connected and all boards powered), i can start to have fun on programming.

I was afraid to make some nonsense connection (like i told before) and messup the boards.
This will be the approach i’ll try, i’ll keep posting my progress here.
Thanks a lot!