Updated readme for new HW

README.md

@@ -2,7 +2,7 @@
 
 This repo contins schematics and code to build a low cost ISM radio to wifi gateway.
 
-Look at [hardware/v2](https://github.com/kanflo/espism/tree/master/hardware/v2) for the hardware and [verification](https://github.com/kanflo/espism/tree/master/verification) for the software used to do hardware verification. The directory [mqtt_sniffer](https://github.com/kanflo/espism/tree/master/mqtt_sniffer) contains an ISM to MQTT sniffer. Blog post [is here](http://johan.kanflo.com/bridging-ism-radio-and-wifi-for-lunch-money/).
+Look at [hardware/v4](https://github.com/kanflo/espism/tree/master/hardware/v4) for the hardware and [verification](https://github.com/kanflo/espism/tree/master/verification) for the software used to do hardware verification. The directory [mqtt_sniffer](https://github.com/kanflo/espism/tree/master/mqtt_sniffer) contains an ISM to MQTT sniffer. Blog post [is here](http://johan.kanflo.com/bridging-ism-radio-and-wifi-for-lunch-money/).
 
 #### Building