From 3d5239f235212b1e15b8f2bac1162ad24c6e8601 Mon Sep 17 00:00:00 2001
From: Kemal Hadimli <disq@users.noreply.github.com>
Date: Fri, 17 Feb 2023 19:49:59 +0000
Subject: [PATCH] Add instructions for LD2410

---
 CMakeLists.txt |  2 +-
 README.md      |  8 +++++++-
 mbedtls_util.c | 22 ----------------------
 3 files changed, 8 insertions(+), 24 deletions(-)
 delete mode 100644 mbedtls_util.c

diff --git a/CMakeLists.txt b/CMakeLists.txt
index d661e5e..270a25c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,7 +29,7 @@ add_compile_options(-Wall
 
 if ((PICO_CYW43_SUPPORTED) AND (TARGET pico_cyw43_arch))
     add_executable(${NAME}
-            main.cpp ledcontrol.cpp ledcontrol.h util.h config.h encoder.cpp encoder.h iot.cpp iot.h presence.cpp presence.h config_iot.h mbedtls_util.c cJSON/cJSON.c cJSON/cJSON.h DFRobot_mmWave_Radar.cpp DFRobot_mmWave_Radar.h
+            main.cpp ledcontrol.cpp ledcontrol.h util.h config.h encoder.cpp encoder.h iot.cpp iot.h presence.cpp presence.h config_iot.h cJSON/cJSON.c cJSON/cJSON.h DFRobot_mmWave_Radar.cpp DFRobot_mmWave_Radar.h
         )
 else()
     add_executable(${NAME}
diff --git a/README.md b/README.md
index 96a207c..dcf856d 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,13 @@ Only a single (right) side of the Pico is used for connections to allow for crea
 
 Pinout diagram is [here](./doc/pinout.png) or [from the back](./doc/pinout-back.png) (courtesy of [pinout.xyz](https://pico.pinout.xyz/))
 
+#### Using LD2410 sensor instead of DFRobot mmWave Radar
+
+Set `PRESENCE_UART_RX_PIN` and `PRESENCE_UART_TX_PIN` to `0` in `config.h` and connect the [LD2410](https://www.aliexpress.com/item/1005004351593073.html) sensor as such:
+  - `VCC` to `VSYS` (Pin 39)
+  - `GND` to any `GND` pin
+  - `OUT` to Pin 22 (see `PRESENCE_PIN`)
+
 ## Usage
 
 ### TL;DR
@@ -108,7 +115,6 @@ And the Pico SDK:
 ```bash
 git clone https://github.com/raspberrypi/pico-sdk
 cd pico-sdk
-git checkout develop # Switch to develop branch
 git submodule update --init
 export PICO_SDK_PATH=`pwd`
 cd ../
diff --git a/mbedtls_util.c b/mbedtls_util.c
deleted file mode 100644
index aa3f235..0000000
--- a/mbedtls_util.c
+++ /dev/null
@@ -1,22 +0,0 @@
-#include "hardware/structs/rosc.h"
-#include "pico/stdlib.h"
-
-/* cribbed from https://github.com/peterharperuk/pico-examples/tree/add_mbedtls_example */
-/* Function to feed mbedtls entropy. May be better to move it to pico-sdk */
-int mbedtls_hardware_poll(void *data, unsigned char *output, size_t len, size_t *olen) {
-  /* Code borrowed from pico_lwip_random_byte(), which is static, so we cannot call it directly */
-  static uint8_t byte;
-
-  for(size_t p=0; p<len; p++) {
-    for(int i=0;i<32;i++) {
-      // picked a fairly arbitrary polynomial of 0x35u - this doesn't have to be crazily uniform.
-      byte = ((byte << 1) | rosc_hw->randombit) ^ (byte & 0x80u ? 0x35u : 0);
-      // delay a little because the random bit is a little slow
-      busy_wait_at_least_cycles(30);
-    }
-    output[p] = byte;
-  }
-
-  *olen = len;
-  return 0;
-}