{"id":8744,"date":"2007-04-24T22:10:00","date_gmt":"2007-04-25T02:10:00","guid":{"rendered":"https:\/\/nuxx.net\/blog\/2007\/04\/24\/pic16f688\/"},"modified":"2026-07-01T11:35:23","modified_gmt":"2026-07-01T15:35:23","slug":"pic16f688","status":"publish","type":"post","link":"https:\/\/nuxx.net\/blog\/2007\/04\/24\/pic16f688\/","title":{"rendered":"PIC16F688"},"content":{"rendered":"

\"EasyPIC4<\/a>EasyPIC4 w\/ PIC16F688 at 12MHz with
rigged connection from hardware UART to on-board level shifter.<\/center><\/p>\n

After some jiggery to get the PIC16F688<\/a> sample I received today talking to the built-in level shifter on the EasyPIC4<\/a> I had no problem getting the basic software for the HMLiberator running and responding to commands. It’s currently running at 12MHz, but as soon as I get some 20MHz crystals it’ll run there. This will give a baud rate just about 0.16% skewed from the specified 9600 baud rate, and I think that’s close enough.<\/p>\n

I still have one problem to sort out before I try plugging it into the car, and that’s with the receive FIFO. With it set at the default of 40 bytes I can get five commands sent and responded to, and then the sixth just fails. As I was testing with a seven-byte command (and 7×5 = 35, just below 40), I think I’m hitting point where the FIFO wraps around (or something — I don’t understand it well enough yet). The incoming commands are of varying size, so I’m not really sure how to work around this yet.<\/p>\n

At least I know where the problem lies. Once that is sorted (or whatever) I’ll plug the thing into the car and see what it does. If that goes well, which I expect it will after some basic software changes, I’ll finish up the v1.0 circuit \/ board design and order a run of boards and make up a first batch of five or so.<\/p>\n","protected":false},"excerpt":{"rendered":"

EasyPIC4 w\/ PIC16F688 at 12MHz withrigged connection from hardware UART to on-board level shifter. After some jiggery to get the PIC16F688 sample I received today talking to the built-in level shifter on the EasyPIC4 I had no problem getting the basic software for the HMLiberator running and responding to commands. It’s currently running at 12MHz,\u2026<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6,11,34],"tags":[],"class_list":["post-8744","post","type-post","status-publish","format-standard","hentry","category-electronics","category-making-things","category-moved-from-livejournal"],"_links":{"self":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/8744","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/comments?post=8744"}],"version-history":[{"count":2,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/8744\/revisions"}],"predecessor-version":[{"id":24564,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/posts\/8744\/revisions\/24564"}],"wp:attachment":[{"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/media?parent=8744"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/categories?post=8744"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nuxx.net\/blog\/wp-json\/wp\/v2\/tags?post=8744"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}