{"id":1207,"date":"2026-03-11T13:50:49","date_gmt":"2026-03-11T05:50:49","guid":{"rendered":"https:\/\/www.ddzheng.cc\/?p=1207"},"modified":"2026-03-11T14:02:19","modified_gmt":"2026-03-11T06:02:19","slug":"modification-of-slc-free-2-afr-gauge-firmware-for-oled-display","status":"publish","type":"post","link":"https:\/\/www.ddzheng.cc\/?p=1207","title":{"rendered":"Modification of SLC FREE 2 AFR Gauge Firmware for OLED Display"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"864\" src=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/1b33ef3f2bbf268f09038ef454015726-1920x864.jpg\" alt=\"\" class=\"wp-image-1211\" srcset=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/1b33ef3f2bbf268f09038ef454015726-1920x864.jpg 1920w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/1b33ef3f2bbf268f09038ef454015726-1200x540.jpg 1200w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/1b33ef3f2bbf268f09038ef454015726-512x230.jpg 512w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/1b33ef3f2bbf268f09038ef454015726-768x346.jpg 768w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/1b33ef3f2bbf268f09038ef454015726-1536x691.jpg 1536w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/1b33ef3f2bbf268f09038ef454015726-2048x922.jpg 2048w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><\/figure>\n\n\n\n<p>The open-source SLC FREE 2 AFR gauge is great, however when paired with OLED 1602 display SEH1602A the original 14point7 supplied firmware does not work properly. The display content is shifted and on same line. <\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"805\" height=\"628\" src=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image-1.png\" alt=\"\" class=\"wp-image-1212\" srcset=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image-1.png 805w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image-1-512x399.png 512w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image-1-768x599.png 768w\" sizes=\"auto, (max-width: 805px) 100vw, 805px\" \/><\/figure>\n\n\n\n<p>There are 2 byte sequences that need to be modified in the LCD.asm file:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"838\" height=\"82\" src=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image.png\" alt=\"\" class=\"wp-image-1208\" srcset=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image.png 838w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image-512x50.png 512w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/image-768x75.png 768w\" sizes=\"auto, (max-width: 838px) 100vw, 838px\" \/><figcaption class=\"wp-element-caption\">Left: original, Right: modified<\/figcaption><\/figure>\n<\/div>\n\n\n<pre class=\"wp-block-code\"><code>LCD_DISP_INC:       equ    06h\nLCD_4BIT_2LINE:     equ    28h\n<\/code><\/pre>\n\n\n\n<p>In order for this modification to preserve across builds <strong>you need to lock the LCD module<\/strong> in Cypress PSoC designer to prevent it from reverting itself back to the original version.<\/p>\n\n\n\n<p>After this modification the OLED display will work properly (first image) and compatibility with traditional LCD display (second image) is also preserved.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1706\" height=\"1279\" src=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/a815dc5ed423ea22f0ffbc96bda82a94.jpg\" alt=\"\" class=\"wp-image-1209\" srcset=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/a815dc5ed423ea22f0ffbc96bda82a94.jpg 1706w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/a815dc5ed423ea22f0ffbc96bda82a94-1200x900.jpg 1200w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/a815dc5ed423ea22f0ffbc96bda82a94-512x384.jpg 512w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/a815dc5ed423ea22f0ffbc96bda82a94-768x576.jpg 768w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/a815dc5ed423ea22f0ffbc96bda82a94-1536x1152.jpg 1536w\" sizes=\"auto, (max-width: 1706px) 100vw, 1706px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1706\" height=\"1279\" src=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/e8a6e89499527bb3a5baf07ee96d240d.jpg\" alt=\"\" class=\"wp-image-1210\" srcset=\"https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/e8a6e89499527bb3a5baf07ee96d240d.jpg 1706w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/e8a6e89499527bb3a5baf07ee96d240d-1200x900.jpg 1200w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/e8a6e89499527bb3a5baf07ee96d240d-512x384.jpg 512w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/e8a6e89499527bb3a5baf07ee96d240d-768x576.jpg 768w, https:\/\/www.ddzheng.cc\/wp-content\/uploads\/2026\/03\/e8a6e89499527bb3a5baf07ee96d240d-1536x1152.jpg 1536w\" sizes=\"auto, (max-width: 1706px) 100vw, 1706px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Compatibility patch with OLED SEH1602A<\/p>\n","protected":false},"author":1,"featured_media":1209,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[48,7,10],"class_list":["post-1207","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-tech","tag-automotive","tag-hw","tag-writeup"],"_links":{"self":[{"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=\/wp\/v2\/posts\/1207","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1207"}],"version-history":[{"count":2,"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=\/wp\/v2\/posts\/1207\/revisions"}],"predecessor-version":[{"id":1214,"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=\/wp\/v2\/posts\/1207\/revisions\/1214"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=\/wp\/v2\/media\/1209"}],"wp:attachment":[{"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1207"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1207"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ddzheng.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1207"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}