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HM-10 clone fun

As part of my early eskate endeavors, I bought a bluetooth dongle for my board to get telemetry from rides. I bought what I thought was an hm-10, but it turned out to be a clone. I originally managed to salvage the situation by following this guide to flash the official hm-10 firmware onto the clone. I slightly deviated from the guide by using a raspberry pi and its gpio pins to do the flashing instead of a ftdi-adapter.

Fast forward to today, with newer and faster bluetooth modules in existence for eskate, the hm-10 has been replaced and sits unused. So the plan was to repurpose it as a wireless serial connection for my cnc. The cnc runs smoothieware, which support uart serial output directly, and all I had to do was hook up the right pins and configure the baud rate. The default baud rate is 9600. A bit slow. In fact, probably too slow for cnc situations where many small movements are happening while the smoopi controller is attempting to stream information back. So I tried bumping up the baud rate to 115200 using AT commands, but this just resulted in communication being flaky. The ends of response text seemed to be cut off. Changing the baudrate to anything in between was also not successful. 9600 seems to be the only usable option.

Most people online don't seem to be too worried about using the hm-10, since it's mostly used for light work. But a few people have mentioned the same flaky behavior. A few places even mentioned improvements in performance after updating their module. Based on the flashing guide, I had v540 on my module, and I later confirmed it with the AT+VERR?. The latest version was v709 and it seemed like they were so confident with their updates that they changed the default baud rate to 115200. Looked promising, but unfortunately the update process uses a windows program so I couldn't update the module without an ftdi-adapter. I eventually stumbled across this guide which suggests I should be able to update with a raspberry pi. Long story short, after following the guide, I now have an unusable bluetooth module. I can probably rescue it by reflashing the original v540 firmware, but that's a project for another time.

Comments

  1. At Skatebolt, we provide a range of high-standard and intellectualized electric skateboards ideal for commuting and speed skating. We have developed the Tornado Series, the Breeze II, and Brisk. Both long-range and high-speed electric skateboards are available for your eskate life. Electric skateboards with off-road wheels are also available for handling more road conditions

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