A very great use case which has been requested by many ?
Location: Denmark
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MasterLink USB adapter
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I am also very interested.
is it possible to control it directly by serial Rs232 (with/without a level converter) ?
Thank you for your excellent work !
is it possible to control it directly by serial Rs232 (with/without a level converter) ?
Thank you for your excellent work !
A very great use case which has been requested by manyYes, certainly makes BL2000 and BL3500 a lot more useful again. :-)
is it possible to control it directly by serial Rs232 (with/without a level converter) ?No, that won't work unfortunately. It's a half-duplex symmetrical bus working at very low voltages (+/- 0.25V). It is a bit similar to RS422 but won't work with such transceiver chips due to the low voltages. Also you have to provide power to the data pins as well as to the ML detect pin. So quite a circuit required and anything else than straight forward.
I misspoke ! Controlling the ML USB adapter by direct by UART instead of USB ! Is there any waiting list" for this device and/or ML to RJ45 adapter ? Thanksis it possible to control it directly by serial Rs232 (with/without a level converter) ?No, that won’t work unfortunately. It’s a half-duplex symmetrical bus working at very low voltages (+/- 0.25V). It is a bit similar to RS422 but won’t work with such transceiver chips due to the low voltages. Also you have to provide power to the data pins as well as to the ML detect pin. So quite a circuit required and anything else than straight forward.
I misspoke ! Controlling the ML USB adapter by direct by UART instead of USB !Ah, okay. On the hardware side that would work. The thing is that ML requires setting some (nowadays) very uncommon parity bits. I'm glad that I found a USB-serial chip that on the receiving side happily ignores any parity errors but let's you set arbitrary bits when sending. So if you are not going through the USB interface it gets a bit more complicated and really depends.
Controlling the ML USB adapter by direct by UART instead of USBI had a similar thought. I considered suggesting adding solder jumpers and some pads to attached wires (or a connector) to the UART signal traces. Without more detail of the design, it is hard to know if suggestions like this make sense or not.
I had a similar thought. I considered suggesting adding solder jumpers and some pads to attached wires (or a connector) to the UART signal traces. Without more detail of the design, it is hard to know if suggestions like this make sense or not.What exactly you'd like to connect there? Right now the RX/TX pins from the ML transceiver circuit are directly connected to the FTDI USB-serial chip. By soldering / removing a few resistors they can also be routed to the 40-way pinsocket. For Raspberry Pis there is a library for bit-banging such things on the GPIOs. Haven't tried it but they promise it works up to 19200 baud (exactly the ML speed) with zero errors.
What happens when there is an actual (real) parity error?Each telegram contains a checksum. If a bit got flipped somehow (messages colliding etc) the checksum won't match and the telegram is ignored or resent. ML and many other low-power machines from that time are using space and mark parity bits for better performance. The first and the last byte is sent with a mark parity bit while the rest of the message is sent with a space parity. The receiver is always set to space parity and so will wake up / get triggered when a parity error occurs. So no need for polling which greatly frees up resources.
I’m looking forward to any updates on functionality, availability, and pricing. This device has the potential to be a lot of fun.I'm currently preparing a summary for everything. Will also provide the schematic. It can receive and transmit ML & DL audio + data. Can act as master or slave. The kit will contain:
- Raspberry Pi compatible MasterDataTool" with RJ45 ML and DIN DL connectors
- RJ45 <-> ML adapter
- short USB-C <-> USB-A cable
- three 3d printed plastic parts that will form a basic housing when assembled with a Raspberry Pi
- € 150 incl. 19% VAT (likely also including shipping cost but not sure yet)
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