Issues with Cyton board & Components
g_congo
UK
I am making the Cyton board from scratch, although after much effort, sourced all of the components and hand soldered everything, the dongle seemed to have worked perfectly and managed to flash it, but I am having major issues with the Cyton board. I still haven't managed to obtain the SD card holder but did get all of the rest and completed the board. Upon powering up the board many things seem to go wrong. One of most noticeable was, when supplying roughly 5v from a NiMH battery and having the switch to BLE, the component U5 (the +3.3V Regulator, i used the: MCP1754T-3302E/OT) , suddenly started becoming extremely hot and I switched to OFF immediately. Trying to upload the firmware is a complete failure and the voltages are not what they are supposed to be. On the OFF position there are still some mV volts present too.
Doing some further research in the components and BOM, I found out that the BOM supplied within the V3 repository are not the ''correct'' ones, and found other BOM from other users containing some different component values, additionally the schematics also contain different values specifically for:
In the V3 BOM supplied for the Cyton board in the Github repository ,
R8, R10 & R11 are all 1KOhm and the diodes:
D8 = CDSU400B (which is a normal diode 80V 100mA having a forward voltage : 1V @ 100mA) and
D9 = CDBU0130L (which is a shottky diode of 30V 100mA having a forward voltage : 350mV @ 10mA). Also
U5 = MCP1754T-3302E/OT
Doing some further research in the components and BOM, I found out that the BOM supplied within the V3 repository are not the ''correct'' ones, and found other BOM from other users containing some different component values, additionally the schematics also contain different values specifically for:
In the V3 BOM supplied for the Cyton board in the Github repository ,
R8, R10 & R11 are all 1KOhm and the diodes:
D8 = CDSU400B (which is a normal diode 80V 100mA having a forward voltage : 1V @ 100mA) and
D9 = CDBU0130L (which is a shottky diode of 30V 100mA having a forward voltage : 350mV @ 10mA). Also
U5 = MCP1754T-3302E/OT
Whilst in contrary the schematic & the other BOM files supplied from other users indicate:
R8 = 1KOhm
R10 = 220KOhm
R11 = 330KOhm and the diodes are BOTH the same
D8 = D9 = CDSU400B
U5 = LP5907
I am currently stuck and do not know where and how to proceed. I am very confused with the components as well, which are the correct ones??? Also can the board work at all without the SD Card holder?
(Please excuse the dumb questions or if I missed some basic understanding of some principles, I do not have a strong electronic background).
If anyone can please answer and help if possible, I will extremely appreciate it.
(Please excuse the dumb questions or if I missed some basic understanding of some principles, I do not have a strong electronic background).
If anyone can please answer and help if possible, I will extremely appreciate it.
Comments
@wjcroft @biomurph could you please help me understand if this is a problem and how to work around this?