# \[in progress] Altimeters Commercial off-shelf altimeters are often required and just nice to have for redundancy. We use the 2 perfectflite stratologger in the avionics bay for main and drogue parachute deployment. ![](https://2333413738-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LB423_rlWTQK_KuQzK5%2F-LXHAWux4IWvOB0A1qNK%2F-LXHB1juQGxZm75TqRec%2F1447035396-sl%2Bcf.jpg-detail.jpg?alt=media\&token=f29192ad-5239-4d61-a1b6-f9f22345aff6) ## Programming For the most part, the altimeters do not need to be programmed once bought. It can be reprogrammed for different modes including ignoring the first X seconds of flight. Refer to the manual linked at the bottom of this page but the reprogramming wires are purchased and housed in the Etcheverry locker. ## Wiring ![](https://2333413738-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-LB423_rlWTQK_KuQzK5%2F-LXHAWux4IWvOB0A1qNK%2F-LXIVjJi-UXVjBVqFjr8%2FAltimeter.jpg?alt=media\&token=b1acc7b0-c55a-4b29-9e86-8c5034c08e56) Positive and negative does not matter for main and drogue as both sides go to an E-match. Same with switch, both sides are the same. However, make sure that the positive and negative sides of the battery is connected properly and listen to beeps for accuracy. **Manual:**