tag:blogger.com,1999:blog-7063183727921268380.post2222932022516102505..comments2024-02-29T06:14:25.154+01:00Comments on TT7 High Altitude Balloon: The Low Power SetupTT7http://www.blogger.com/profile/11095378058232471221noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-7063183727921268380.post-64629920322850650302017-10-08T14:24:51.042+02:002017-10-08T14:24:51.042+02:00Hi Richard,
I use only the u-blox module without ...Hi Richard,<br /><br />I use only the u-blox module without any backup battery or power switching on TT7F. As long as the module is powered the saved configuration stays in the RAM. You can provide separate backup power supply to the V_BCKP pin while in my setup it is wired straight to VCC. As you observed, the tracker re-initializes the GPS every time there is a loss of power (generally nighttime). In later versions, I added a reset instruction (0x06 0x04) ahead of turning of the NMEA output, because on occasions the MCU may reset or loose power while the GPS stays on. One thing to watch out for is waiting for the u-blox module to finish its power-up sequence. It won't responde to any instructions until its done. I use simple delays, another way is checking whether the module responds with an ACK message.<br />One thing about saving the settings. In case of entering the ON/OFF mode, you should send the UBX-CFG-CFG immediately after the UBX-CFG-RXM instruction. If you do it prior, the module won't know it is supposed to be in the power saving mode. If you do it too late, the module may already be powered down.<br /><br />TomasTT7https://www.blogger.com/profile/11095378058232471221noreply@blogger.comtag:blogger.com,1999:blog-7063183727921268380.post-2887878293545544792017-10-08T08:14:26.600+02:002017-10-08T08:14:26.600+02:00Hi,
This is a great rundown of your project. A qu...Hi,<br /><br />This is a great rundown of your project. A query when you run UBX-CFG-CFG to save your settings prior to GPS shutdown - it talks about battery backed up RAM. Are you running a cell in your circuit to specifically do this? It looks as if the rest of your tracker just operates on solar and capacitors which would seem to be a non-permanent source of power. Or is it simply configured during daylight hours when the solar power is working , and on wake up at sunrise the full program running the shut off of the NMEA sentences runs again?<br /><br />Many thanksRichardhttps://www.blogger.com/profile/06660817097798846593noreply@blogger.comtag:blogger.com,1999:blog-7063183727921268380.post-67937703526287656332017-07-03T18:00:47.522+02:002017-07-03T18:00:47.522+02:00I really appreciate all of the documentation you a...I really appreciate all of the documentation you are providing of your process and findings. I'm in the process of designing and building a floating pico balloon payload and this information has been very helpful to me.<br /><br />Thanks!<br /><br />Jared (N7SMI)Jaredhttps://www.blogger.com/profile/07816171234506096653noreply@blogger.com