From b73ad68abd767c8196234f0bb4ffd436005fad46 Mon Sep 17 00:00:00 2001 From: James <13262021+james-coder@users.noreply.github.com> Date: Fri, 9 Feb 2024 15:46:11 -0700 Subject: [PATCH] Heltec LoRa 32 v3.1 added Heltec LoRa 32 v3.1 has two schematic changes from v3.0 Two people have mentioned it on Discord and one person has mentioned it on Facebook. OLED screen appears to show a booted Meshtastic. (That shouldn't be an issue as the changes are PSU + ESP32-S3 RF, but at least the 3.3V rail is maybe not impacted?) https://discord.com/channels/867578229534359593/871553168369148024/1202361664608149555 https://discord.com/channels/867578229534359593/919642584480112750/1171093224060883065 https://www.facebook.com/groups/730536684339042/posts/1486317198760983/ V3.1 schematic: https://resource.heltec.cn/download/WiFi_LoRa_32_V3/HTIT-WB32LA(F)_V3.1_Schematic_Diagram.pdf v3.0 schematic (deleted from Heltec's website!) https://web.archive.org/web/20221127054612/https://resource.heltec.cn/download/WiFi_LoRa32_V3/HTIT-WB32LA(F)_V3_Schematic_Diagram.pdf --- docs/hardware/devices/heltec/index.mdx | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/docs/hardware/devices/heltec/index.mdx b/docs/hardware/devices/heltec/index.mdx index 813a7179..9f26368b 100644 --- a/docs/hardware/devices/heltec/index.mdx +++ b/docs/hardware/devices/heltec/index.mdx @@ -96,6 +96,27 @@ Image Source: [Heltec]( + + +## HELTEC v3.1 + +On the top right side of the board where it normally says "V3" next to the U.FL/IPEX antenna connector, there is a "V3.1" instead of "V3". These started appearing around November 2023. + +[V3.0 schematic](https://web.archive.org/web/20221127054612/https://resource.heltec.cn/download/WiFi_LoRa32_V3/HTIT-WB32LA(F)_V3_Schematic_Diagram.pdf) + +[V3.1 schematic](https://resource.heltec.cn/download/WiFi_LoRa_32_V3/HTIT-WB32LA(F)_V3.1_Schematic_Diagram.pdf) + +The schematic between V3.0 and V3.1 is virtually identical, with only two differences: + +- V3.0 has a [FDG6322C](https://www.mouser.com/datasheet/2/308/1/FDG6322C_D-2312203.pdf) in the power supply circuitry. (FDG6322C is a dual N & P channel digital FET on the output of the LDO regulator. Seems like a cost cutting measure, but it might impact the maximum current or stability of the 3.3V rail.) + +- V3.0 had different ESP32-S3 antenna filters: + - V3.0: L11 = 1.6nH, C15 = 6.9pF, C24 = 2.4pF + - V3.1: L11 = 1.8pF(?), C15 = 2.7nH (?), C24 = 1.8pF +Question marks above on V3.1 because pF are typically capacitors and nH are typically inductors. Did they mess something up, or did this require an odd swap like this? TODO: someone please confirm the V3.1 ESP-S3 Bluetooth and Wifi are functional with Meshtastic. + + + ## HELTEC Wireless Stick Lite V3