The pH FeatherWing [https://iorodeo.com/products/phfeatherwing] is sold as an unassembled kit. The kit includes the pH FeatherWing v0.2 board (PCB with all of the smt components), and a set of through-hole components. These are i) 3-pin screw terminal connector (blue), ii) 12-pin and 16-pin headers and

The pH FeatherWing [https://iorodeo.com/products/phfeatherwing] is a single channel pH electrode amplifier based on Texas Instrument's LMP7721 [http://www.ti.com/lit/ds/symlink/lmp7721.pdf] ultra low input bias current (3 fA) precision operational amplifier. The design of the pH electrode amplifier closely follows Texas Instrument's