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I'm planning to do a simple DIY car that is controlled with a smartphone. I'm new to DIY electronics, and would like to get all of the needed electronic components with a single order. Could you check out this list and tell me if i'm missing anything essential?

  • RPi3B
  • 2x DC motors
  • Motor controller
  • Power supply or batteries
  • Non-electronic stuff (4x wheels, chassis etc.)
  • Wires (What type of wire should I buy?)

As i have understood the RPi3B comes with onboard WiFi and bluetooth and has the ability to setup a hotspot, so all I need is a smartphone and programming skills for a wireless connection (?)

SlySven
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saldukoo
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2 Answers2

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  • Does your motor driver support controlling 2 motors?
  • Have you thought about talking to your motor driver(from the Pi)?
    • keep in mind the Bluetooth does use up the Pi's UART! (see comments for more information)
  • For quick wiring, those are great, either many of them, or in bulk like the one I just found(you could also tear them apart when needed)
  • For solid constructions, you should consider soldering classic copper wires as well as getting connectors, to not have to solder to your components directly
  • Yes, the Pi3 has WiFi and BT, but you only need 1 of them for your remote control, unless the Pi itself is supposed to be controlling the car remotely
    • e.g. Smartphone -> Wifi -> Pi -> Bluetooth -> RC car

Regarding programming, you would need to write both sides on your own, a smartphone app, utilizing either BT or WiFi and the Pi's response, which will be talking to your motor driver.

mystery
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  • Um, are you sure "the Bluetooth does use up the Pi's UART" on the Pi 3? It's my understanding that the bluetooth node uses `ttyAMA0`, but that is **not** the UART on the breakout -- it uses a *different node* than previous models, `ttyS0`. They should both be usable at the same time. – goldilocks Jun 28 '16 at 14:36
  • Yes, I am. ttyS0 is just the mini UART, which is not reliable as it is based on the cpu clock. – mystery Jun 28 '16 at 14:37
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    Ah. Well at least there appears to be a way to swap one for the other at boot time [see the end, about device tree, here](http://raspberrypi.stackexchange.com/a/45571/5538). Otherwise I will be mailing mine straight back when it get here, lol. – goldilocks Jun 28 '16 at 14:44
  • That is indeed possible but I would not recommend it for neither the motor controller nor bluetooth since communication failures won't be fun there. The only workaround would be to set the CPU frequency to a fixed value. Other than that, the mini UART does not lack crucial features his fully fledged brother provides in such applications. [See page 10](https://cdn-shop.adafruit.com/product-files/2885/BCM2835Datasheet.pdf) – mystery Jun 28 '16 at 14:47
  • @mystery The UART is only unreliable if the core clock frequency changes. You can set a fixed core clock frequency and take a small performance hit (the performance hit wouldn't even kick in for this sort of application). – joan Jun 28 '16 at 15:30
  • Would be interesting to see this work with NodeJS running on the PI :P – Callum Linington Jun 28 '16 at 18:39
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Every thing is fine just for a simple car. If you want you can add some LED's . And in case of wires use Jumper Wires

prabhakar-sivanesan
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