From f97119cb48801b28307fbe69f8480c53a63eeba7 Mon Sep 17 00:00:00 2001
From: leo <leo.lemaire007@orange.fr>
Date: Sun, 27 Nov 2022 11:11:15 +0100
Subject: [PATCH] co2 characteristic presentation format

---
 components/BTlib/BTlib_nimble.c         | 25 ++++++++++++--
 components/BTlib/include/BTlib_nimble.h | 44 +++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/components/BTlib/BTlib_nimble.c b/components/BTlib/BTlib_nimble.c
index a676f8c..4997a17 100644
--- a/components/BTlib/BTlib_nimble.c
+++ b/components/BTlib/BTlib_nimble.c
@@ -50,6 +50,14 @@ ES_char_descr_t hum_char_descr = {
 	.measurement_uncertainty = 30,
 };
 
+char_pres_format_t CO2_char_pres_format = {
+	.format = FORMAT_INT16,
+	.exponent = 0,
+	.unit = PPM_UNIT_UUID,
+	.namespc = 1,
+	.descr = NSP_DESC_MAIN,
+};
+
 struct ble_hs_adv_fields adv_fields = {
 	.flags = BLE_HS_ADV_F_DISC_GEN | BLE_HS_ADV_F_BREDR_UNSUP,
 	.tx_pwr_lvl_is_present = 1,
@@ -85,6 +93,11 @@ static struct ble_gatt_svc_def gatt_svr_svcs[] = {
 						.att_flags = BLE_ATT_F_READ,
 						.access_cb = gatt_svr_chr_access_co2,
 					},
+					{
+						.uuid = BLE_UUID16_DECLARE(CHAR_PRES_FORMAT),
+						.att_flags = BLE_ATT_F_READ,
+						.access_cb = gatt_svr_chr_access_co2,
+					},
 					{ 0 },
 				},
 			},
@@ -135,8 +148,16 @@ static int gatt_svr_chr_access_co2(uint16_t conn_handle, uint16_t attr_handle, s
 		case BLE_GATT_ACCESS_OP_READ_CHR:
 			rc = os_mbuf_append(ctxt->om, &main_app_conf->measure->co2, sizeof(main_app_conf->measure->co2));
 		break;
-		case BLE_GATT_ACCESS_OP_READ_DSC:
-			rc = os_mbuf_append(ctxt->om, &CO2_char_descr, 11); // hardcoded size 'cause struct gets padded to 12bytes
+		case BLE_GATT_ACCESS_OP_READ_DSC:{
+			uint16_t uuid = ble_uuid_u16(ctxt->dsc->uuid);
+			switch(uuid){
+				case ES_MEASUREMENT_UUID:
+					rc = os_mbuf_append(ctxt->om, &CO2_char_descr, 11); // hardcoded size 'cause struct gets padded to 12bytes
+				break;
+				case CHAR_PRES_FORMAT:
+					rc = os_mbuf_append(ctxt->om, &CO2_char_pres_format, 7);
+				}
+			}
 		break;
 	}
 	return rc == 0 ? 0 : BLE_ATT_ERR_INSUFFICIENT_RES;
diff --git a/components/BTlib/include/BTlib_nimble.h b/components/BTlib/include/BTlib_nimble.h
index 846965a..07ef39c 100644
--- a/components/BTlib/include/BTlib_nimble.h
+++ b/components/BTlib/include/BTlib_nimble.h
@@ -14,6 +14,10 @@
 #define CHAR_TEMP_UUID 0x2A6E
 #define CHAR_HUM_UUID 0x2A6F
 #define CO2_SENSOR_APPEARANCE 0x054A
+#define CHAR_PRES_FORMAT 0x2904
+#define PPM_UNIT_UUID 0x27C4
+#define NSP_DESC_MAIN 0x0106
+
 #define DEFAULT_NAME "CO2_ble"
 #define DEFAULT_NAME_LEN 7
 
@@ -67,6 +71,37 @@ enum {
 	ES_APP_SOLAR,
 };
 
+enum {
+	FORMAT_RFU,
+	FORMAT_BOOL,
+	FORMAT_UINT2,
+	FORMAT_UINT4,
+	FORMAT_UINT8,
+	FORMAT_UINT12,
+	FORMAT_UINT16,
+	FORMAT_UINT24,
+	FORMAT_UINT32,
+	FORMAT_UINT48,
+	FORMAT_UINT64,
+	FORMAT_UINT128,
+	FORMAT_INT8,
+	FORMAT_INT12,
+	FORMAT_INT16,
+	FORMAT_INT24,
+	FORMAT_INT32,
+	FORMAT_INT48,
+	FORMAT_INT64,
+	FORMAT_INT128,
+	FORMAT_FLOAT32,
+	FORMAT_FLOAT64,
+	FORMAT_IEEE11073_SFLOAT16,
+	FORMAT_IEEE11073_FLOAT32,
+	FORMAT_IEEE20601,
+	FORMAT_UTF8,
+	FORMAT_UTF16,
+	FORMAT_OPAQUE,
+};
+
 enum{
 	ES_SVC_IDX,
 };
@@ -87,6 +122,15 @@ struct ES_char_descr {
 };
 typedef struct ES_char_descr ES_char_descr_t;
 
+struct char_pres_format {
+	uint8_t format;
+	uint8_t exponent;
+	uint16_t unit;
+	uint8_t namespc;
+	uint16_t descr;
+};
+typedef struct char_pres_format char_pres_format_t;
+
 void initBle(configuration_data_t* main_conf);
 void ble_sensor_notify();
 #endif