protocentral / protocentral_ads1293 Goto Github PK

Hello,
I am looking to your ADS1293 breakout and I have some questions about your design:

• What is the reason of the solder jumper SIG_SEL ? The connection between the Wilson Control Terminal can be done in software, setting the WILSONINT-bit to 1 in WILSON_CN (address 0x10), see figure 48 in the datasheet. With a soldered jumper you may run in problems and you will lose software reconfiguration.
• What is the reason for the additional oscillator on the board? Reading the datasheet, the ADS1293 generates the needed clock with an internal oscillator, supported from the external crystal and capacitors. The clock-pin can be used for two purposes, when cascading multiple ADS1293. The main chip configures clock as output, while the daughter chips getting synchronized clock, using the clock pin as input. It looks like, that I can't cascade your boards, without unsoldering the additional clock source.
• Furthermore you have two 10pF capacitors close to the crystal, while the datasheet asks for 20pF each. What is the reason for this decision?
• Having a logic level converter on board looks like a perfect solution towards the Arduino solutions. With the possibility for two voltages, why you have no solder jumper on VSS to allow 5V, if available. As the recommended analog supply voltage should be between 2.7 and 5.5V, it would be nice, to use the wider range, if a second voltage is available.
• Why is SYNCB not available as a pin? This is also needed for cascading multiple boards.