Prints redered markdown. Paper not padded after print finishes. Manual pull is required at the moment to get the full print area.
- Service ID:
49535343-fe7d-4ae5-8fa9-9fafd205e455 - Characteristic value to write to:
49535343-6daa-4d02-abf6-19569aca69fe - Characteristic value to receive from the printer:
49535343-1e4d-4bd9-ba61-23c647249616This is a NOTIFY character.
- BLE has a max data packet of 512, means 502 bytes of useful data. However, I found out that each packet should not contain unfinished lines otherwise they tear. So I rounded to 480 for 48 bytes per line on P1.
All send and receive data command byte are in const.txt. Send and receive has (almost) same data structure. When a packet is received, its also begin with 0x02 and end with 0x03.
2nd byte is command byte, then the first 5 and last 5 bytes are not very useful since I don't care about checksums so I discarded them. Then the last 11 bytes of whats remaining seems to be some kind of redundant addon data, so they are disregarded as well. Then only a handful of bytes will remain and they are easier to decode.
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Reading ASCII stringed values (SN, model, board version...) : Just do the right truncating and decode the rest as ASCII.
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Battery status: Send command 16, only one byte will remain after all the truncating. That byte is the percentage value directly usable. Do not divide it again by 255.
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Get heat density: Send 28, then look at the first byte returned. Same as battery status. Do not divide by 255.
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Feed line: The printer will feed blank paper of a specific length. Send command 26, then immediately followed by the amount of lines(in pixel) to be fed encoded as payload data.
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Power-down time: Send 31, get a 2 byte integer. Notice it's little endian means reverse their byte order to read them. i.e.
[16,14]or0x100Eindicate 3600 seconds, not 4110.
Some commands in the list are not implemented on the P1 model. I do not know whether it works on any other model.