IV-3 VFD confusion
So you want to build Axiris's IV-3 shield for Arduino , sourcing the IV-3 VFD tubes yourself, from any of the numerous ebay sellers, as I did. Firstly, it is important to note that, although the assembly manual for IV-3 shield refers to it as "IV-3/IV-3a/IV-6 VFD shield for Arduino", which would make you think one could install either IV-3, IV-3A or IV-6 tubes, this is not quite the case. The reason is the difference in pin configuration: IV-3: 9-segment + dot, 14 pins (1 not connected) (pin configuration is bottom view ) IV-3A and IV-6: 7 segment + dot, 12 pins (1 not connected) (pin configuration is bottom view ) and then, there is IV-3 v-82 , which I bought on ebay: 7 segment + dot, 14 pins (3 not connected) (pin configuration is top view ) IV-3 v-82 (as I named it, based on the printing on the back of the tube), is an amalgamation between IV-3 and IV-3A: - can be found in either 7 segment or 9 segment (+ dot), although only 7 segments are connected; - has 14 pins (a