Currently there are 2 options to make JLCPCB’s full-color PCBs extremely cheap to order:

  • One-time coupon for $10 specifically for multicolor PCBs. Economy option for colorful PCB (i.e. 10x10cm, 2 layers) costs around 8$, so with this coupon you get the PCB almost for free. "Almost" because price cannot go below 1$ due to taxes and duties limitation (according to JLCPCB at least), and you still have to pay import duties and shipping costs.

  • Points on Oshwlab can be exchanged 1-to-1 for multicolor PCB coupons (i.e. 10 points for 10$). For other types of PCBs the conversion rate is 10:1 (10pts for 1$), so RGB PCBs are a steal and much cheaper than normal ones. Oshwlab points can be earned by posting open source projects (50 pts, they are manually checked for quality though), posting on forum (5pts) and just logging in (2pts per day). So just making one post gives you a 5$ discount of RGB PCB!

On top of that, there currently is a Oshwlab/JLCPCB contest where they give points for making and open-sourcing full-color PCB projects. Participants get 300pts (which amounts to 30$ of parts on LCSC for example), winners get 100$ coupon, which is not nearly as attractive as it looks, because your order must be above 100$ for coupon to take effect. You cannot split 100$ into several smaller purchases.

So, to join the fest and get colorful PCBs, I quickly made and ordered 2.

Controller Mk1-alpha

The first one is a new iteration of an Arduino Nano expansion board, which is also happens to be a new iteration of a RC controller board.

Compared to previous Arduino Nano expansion board, the new one also supports Arduino Pro Mini, so will accommodate RP2040 and nRF52840 boards in same format (these are popular in mechanical keyboard communities). It also has space for 2 motor DRV8833 modules (so up to 4 motors), and places to solder 2 potentiometers. OLED display and 2 buttons are still in place. So in these regards it’s an extension of v1 in every way (it’s also larger). The incompatible change is that the motors are now controlled with PWM+DIR pins, not PWM1+PWM2. This requires only 1 PWM pin per motor instead of 2, a change that allowed 4 motors in the first place. (Due to fewer pins on Arduino Pro Micro, only 3 motors are supported by it).

However, the most significant change is that this time the board is designed to use of Amperka Troyka modules ecosystem. The reason for this is increased versatility and ability to use the board for more applications by swapping the modules on top.

Using joystick modules, for example, will allow the PCB to be used as a remote control or a gamepad (provided Rf/USB-capable MCU is used).

Mounting a steering wheel should also be possible.

That’s the reason it’s officially called "Controller Mk1-alpha" as a continuation of Controller Mk0. The new board does not directly support LILYGO T-Display though.

RC Truck tester board

Second PCB is a tester breakout board for BLE-RC and motorboard-py32 board. Here is its dedicated project page.

Center of PCB has a picture of a truck and it has LEDs in necessary places. After connecting BLE-RC board to it, the LEDs should work as expected. There are connectors for a DC motor and a servo.

Large part of the board is also dedicated to motorboard-py32 expansion board. It’s supposed to go into truck trailer (or stay in the same truck if it adds lights/motors to the truck itself). Its functions are much less defined, so they are visualized by simple row of LEDs. Motor ports for motorboard are also there.

In both cases, bottom image is courtesy of AI (Google Gemini and Adobe Firefly).

P.S. This post is not sponsored in any way, I just like JLCPCB service.