From dbf35e8b60ba2707a0494c5c71d33d7ed9fe7e50 Mon Sep 17 00:00:00 2001
From: George Norton <george_norton_uk@hotmail.com>
Date: Tue, 22 Aug 2023 23:00:36 +0100
Subject: [PATCH] Increase filter stages to 20. We cant quite run that many
 though.

---
 firmware/code/bqf.h                 |  6 +++---
 firmware/code/configuration_types.h | 18 ++++++++++--------
 2 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/firmware/code/bqf.h b/firmware/code/bqf.h
index a347575..5a38ccb 100644
--- a/firmware/code/bqf.h
+++ b/firmware/code/bqf.h
@@ -41,9 +41,9 @@ typedef struct _bqf_mem_t {
     fix3_28_t y_2;
 } bqf_mem_t;
 
-// In reality we do not have enough CPU resource to run 8 filtering
-// stages without some optimisation.
-#define MAX_FILTER_STAGES 16
+// More filters should be possible, but the config structure
+// might grow beyond the current 512 byte size.
+#define MAX_FILTER_STAGES 20
 extern int filter_stages;
 
 extern bqf_coeff_t bqf_filters_left[MAX_FILTER_STAGES];
diff --git a/firmware/code/configuration_types.h b/firmware/code/configuration_types.h
index 4b638ac..051edd4 100644
--- a/firmware/code/configuration_types.h
+++ b/firmware/code/configuration_types.h
@@ -17,8 +17,8 @@
 #include <stdint.h>
 
 #define FLASH_MAGIC 0x2E8AFEDD
-#define CONFIG_VERSION 2
-#define MINIMUM_CONFIG_VERSION 1
+#define CONFIG_VERSION 3
+#define MINIMUM_CONFIG_VERSION 3
 
 enum structure_types {
     // Commands/Responses, these are container TLVs. The Value will be a set of TLV structures.
@@ -53,18 +53,20 @@ typedef struct __attribute__((__packed__)) _tlv_header {
 typedef struct __attribute__((__packed__)) _filter2 {
     uint8_t type;
     uint8_t reserved[3];
-    double f0;
-    double Q;
+    float f0;
+    float Q;
 } filter2;
 
 typedef struct __attribute__((__packed__)) _filter3 {
     uint8_t type;
     uint8_t reserved[3];
-    double f0;
-    double db_gain;
-    double Q;
+    float f0;
+    float db_gain;
+    float Q;
 } filter3;
 
+// WARNING: We wont be able to support more than 8 of these filters
+// due to the config structure size.
 typedef struct __attribute__((__packed__)) _filter6 {
     uint8_t type;
     uint8_t reserved[3];
@@ -98,7 +100,7 @@ typedef struct __attribute__((__packed__)) _flash_header_tlv {
 
 typedef struct __attribute__((__packed__)) _preprocessing_configuration_tlv {
     tlv_header header;
-    double preamp;
+    float preamp;
     uint8_t reverse_stereo;
     uint8_t reserved[3];
 } preprocessing_configuration_tlv;