Saturday, November 14, 2020

STM32 Update

11/24/2020: Done a bit of reorganizing here. In the right panel are quick links to the contents of the site. Hope they help you find what you're looking for. On the orders page is a listing of what's currently available. You can just copy and past the listing to your email with your selections indicated and save some time. In the How To page I've added a MaxESP3 assembly tutorial. I'm going through a few hundred emails to mine questions and answers for the FAQs, so there's nothing there at the moment.

11/14/2020: Frankly, I don't know when the STM32F103C8 supply/situation is going to be resolved. In the interim I'm dropping the price of the MaxESP3 to $40 to fill the gap. 
Here's the situation; STM has introduced some new processors and the supply of STM32F103C8 BluePills with 128K have disappeared. There are 64K versions around, but we can't use them. Whether this is a marketing ploy to push their newer designs or just poor planning is your best guess. RobotDyn has stopped taking orders on AliExpress for the STM32F303CC, the only proven replacement. The ones I ordered haven't moved in 5 weeks. It appears the ST or the devboards makers weren't prepared for the demand.
There are other sellers, but their devboards are not pin compatible with the F103C8 and they are running $11. The F303CC runs at 72MHz, a bit slower than the Teensy 3.2, but still half the speed of the ESP32. It has the required memory and can have a RTC added. Right now these are in short supply or too expensive for the STM32 kit.

Other possibilities are the CS or CKS32F103C8 and, APM32F103CB.
Due to time constraints, I am going to have to stop offering the assembling and testing of kits. I am working on a project for an assembled kit I hope to offer in the new year.

Kits Available

MaxESP3 - $40 Fully featured controller at a great price, moderate skill level.

MiniPCB1 and 2 - $45 Powerful 600MHz ┬Áprocessor in compact packages. Easy to assemble and program with Teensyduino.

STM32 - $22.50 Everything to build the BluePill, except the BluePill. 

SHC ESP32 - $25 Features the 1.3" OLED display.

BHC - $10 Includes PCB, Momentary switches and RJ-12.

LV8729 or S109 step motor drivers $6 with Kit order.

PCBs, any of the PCBs for the kits may be ordered individually. $6 shipped in the U.S. $12 elsewhere.

Wemos D1 mini Pro and antenna substitution for D1 mini - $6.50.

HC-05 and BT adapter PCB for MiniPCB2 and STM32 - $9.

EQ-5 type mount motor brackets 2 @ $15. Provide 4mm of adjustment.

Aluminum enclosure for MaxESP3 -$14. Limited stock.

Aluminum enclosure for MiniPBC2 - $10. Limited stock.

ABS enclosure for the MiniPBC1 and BHC - $4


  1. Hi George,

    Please see my email to you re: kit order. Thanks!

  2. Hi
    If i get the 1 MaxESP3 and the LV8729 drivers 1 Aluminum enclosure , EQ-5 type mount motor brackets 2 , 1 spare PCB and 1 SHC ESP32 - $25 Features the 1.3" OLED display. will this be all i need to complete the project
    Thanks Chris

    1. You'll need NEMA 17 steppers, motor cables pulleys and belts I use 48T/16T 138mm belts.

      Thanks, Geo.

    2. ok great ,Please can you send me an invoice
      Thanks chris

  3. Hi George,

    Pls see my email to you re: I want to order a kit's. Thx!

  4. Hi George,

    Pls see my email to you re: "Payment". Thx!

  5. Hi George,

    Pls see my email to you re: "When should I wait for my MiniPCB2". Thx!

    1. Goes out today. Usually 6-10 days to Europe.