Thursday, June 24, 2021

5/6/2021: New Products: Assembled Controllers I've decided to sell a couple of assembled OnStep controllers to meet the needs of those who have kit assembly hesitancy. The first of these is the ESPduino/Hujer controller. This controller starts at $27.50 assembled and tested. There is no other way to get into OnStep goto other than stealing it! This controller is based on a full fledged ESP32S running at 240MHz, not an Arduino Mega.

The second is also a ESP32S based on Alain Kinlough's MiniESP3. This is basically a MaxPCB3 without the extra two driver slots, but with all the Max's other feature support. It uses surface mount devices for ease of assembly and reliability. Details here.

2/13/2021: I have successfully flashed APM32F103CB µcontroller being sold by RobotDyn. So it seems there is a reasonably priced replacement for the STM32F103C8, which cannot reasonably relied on to have the 131K flash needed to load OnStep. ver. 4.23. The RobotDyn "Black Pill" STM32F303cc can also be used but is too pricey to include in a $30 kit. It is also generally unavailable for purchase. 

I don't see much point in offering the STM32 at $35 again when the fully featured MaxESP3 is available for $40. For the time being I will offer the STM32 with the APM32F103CB for $30 and without the processor for $25. When the current inventory of STM32 parts is exhausted I will have to reevaluate its future as a kit.

12/9/2020: Still working on the STM flashing issue. Drew has had luck using STM-Flash.exe (SourceForge) to upload the Arduino IDE compiled OnStep software to the CKS and APMF103C8 STM32 clones (AVR licensed). Trying to get a handle on using it. 

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 - $49 Fully featured controller at a great price, moderate skill level.

MiniPCB1 and 2 - $50 Powerful 600MHz µprocessor in compact packages. Easy to assemble and program with Teensyduino.

STM32 - $25.00 Everything to build the BluePill, except the BluePill. 
            $35 Same, but with a 131K flash STM32 or duplicate.

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

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

PCBs, any of the PCBs for the kits may be ordered individually. $8 shipped in the U.S. $14 elsewhere.

Wemos D1 mini with antenna substitution for D1 mini - $6.

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

EQ-5 type mount motor brackets 2 @ $22. Provide 4mm of adjustment.

Aluminum enclosure for MaxESP3 -$10. Limited stock.

Aluminum enclosure for MiniPBC2 - $8. Limited stock.

ABS enclosure for the MiniPBC1 and BHC - $4

See menu above right for how to place an order.


  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. This comment has been removed by a blog administrator.

  5. Hi George,

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

  6. Hello George, trying to contact you for some parts.
    Seems your old email is not working.

  7. Please contact me if possible:

  8. - Mapyro
    Find, Las Vegas. Hotel and 태백 출장안마 Casino, Nevada. 3131 Las Vegas Blvd S, Las Vegas, NV 안성 출장마사지 89109. 서귀포 출장안마 (702) 770-3121. 청주 출장마사지 Free 전주 출장안마 Parking. Rating: 2.5 · ‎220 reviews