Building an Infrared Remote Code Learner for my Brainwaves Appliance Controller (part 4)

5 Sep 2014

This is the third blog update after I started to build the infrared remote control code learner (here are links to the previous posts: 1, 2, 3 ) . I thought it would go faster, but it turned out to be a quite difficult task, which I am still working on. So far, as I showed in my previous blog, I built a circuit and algorithm that captures the infrared signal from a remote control, decodes it, measures the infrared carrier frequency (which can have various values typically between 30kHz and 60kHz), and encodes it in a format that can be further stored in the EEPROM memory block of the PsoC5LP chip. In this update I will show how I store the infrared remote control codes into the EEPROM array inside the Cypress PSoC5LP chip and how I read it back. Next step would be to reconstruct the infrared signal and send it to an IR LED. When done with this task I will implement the code learner into my brainwaves appliance controller project so users can “teach” the brainwaves appliance controller specific codes needed to control their TVs, cable or satellite receivers, and other electronic devices that use infrared remote control.

So let’s take a look on how I have approached the code writing into EEPROM memory block task. First, I need to fit 8 infrared remote control codes into the 2k EEPROM memory inside the PSoC5LP. Each remote control code is sampled and then encoded in a compressed format that fits in an array of 224 locations.

For each infrared remote control code I need to store an array of size 224 uint8 values and additionally the infrared carrier frequency and unit interval. In the table below I am showing how I mapped the 2k EEPROM block inside PSoC5LP to store these 8 infrared remote control codes. There are 128 rows and each row has 16 locations of 8 bits each.

EEPROM Memory Mapping

Row number	mem_bas_index
0	0	code_0_IR_remote	code0_IR_carrier_freg_and_unit_interval
1	16		code0_IR_carrier_on array [0-15]
2	32		code0_IR_carrier_on array [16-31]
3	48		code0_IR_carrier_on array [32-47]
4	64		code0_IR_carrier_on array [48-63]
5	80		code0_IR_carrier_on array [64-79]
6	96		code0_IR_carrier_on array [80-95]
7	112		code0_IR_carrier_on array [96-111]
8	128		code0_IR_carrier_off array [0-15]
9	144		code0_IR_carrier_off array [16-31]
10	160		code0_IR_carrier_off array [32-47]
11	176		code0_IR_carrier_off array [48-63]
12	192		code0_IR_carrier_off array [64-79]
13	208		code0_IR_carrier_off array [80-95]
14	224		code0_IR_carrier_off array [96-111]
15	240
16	256	code_1_IR_remote	code1_IR_carrier_freg_and_unit_interval
17	272		code1_IR_carrier_on array [0-15]
18	288		code1_IR_carrier_on array [16-31]
19	304		code1_IR_carrier_on array [32-47]
20	320		code1_IR_carrier_on array [48-63]
21	336		code1_IR_carrier_on array [64-79]
22	352		code1_IR_carrier_on array [80-95]
23	368		code1_IR_carrier_on array [96-111]
24	384		code1_IR_carrier_off array [0-15]
25	400		code1_IR_carrier_off array [16-31]
26	416		code1_IR_carrier_off array [32-47]
27	432		code1_IR_carrier_off array [48-63]
28	448		code1_IR_carrier_off array [64-79]
29	464		code1_IR_carrier_off array [80-95]
30	480		code1_IR_carrier_off array [96-111]
31	496
32	512	code_2_IR_remote	code2_IR_carrier_freg_and_unit_interval
33	528		code2_IR_carrier_on array [0-15]
34	544		code2_IR_carrier_on array [16-31]
35	560		code2_IR_carrier_on array [32-47]
36	576		code2_IR_carrier_on array [48-63]
37	592		code2_IR_carrier_on array [64-79]
38	608		code2_IR_carrier_on array [80-95]
39	624		code2_IR_carrier_on array [96-111]
40	640		code2_IR_carrier_off array [0-15]
41	656		code2_IR_carrier_off array [16-31]
42	672		code2_IR_carrier_off array [32-47]
43	688		code2_IR_carrier_off array [48-63]
44	704		code2_IR_carrier_off array [64-79]
45	720		code2_IR_carrier_off array [80-95]
46	736		code2_IR_carrier_off array [96-111]
47	752
48	768	code_3_IR_remote	code3_IR_carrier_freg_and_unit_interval
49	784		code3_IR_carrier_on array [0-15]
50	800		code3_IR_carrier_on array [16-31]
51	816		code3_IR_carrier_on array [32-47]
52	832		code3_IR_carrier_on array [48-63]
53	848		code3_IR_carrier_on array [64-79]
54	864		code3_IR_carrier_on array [80-95]
55	880		code3_IR_carrier_on array [96-111]
56	896		code3_IR_carrier_off array [0-15]
57	912		code3_IR_carrier_off array [16-31]
58	928		code3_IR_carrier_off array [32-47]
59	944		code3_IR_carrier_off array [48-63]
60	960		code3_IR_carrier_off array [64-79]
61	976		code3_IR_carrier_off array [80-95]
62	992		code3_IR_carrier_off array [96-111]
63	1008
64	1024	code_4_IR_remote	code4_IR_carrier_freg_and_unit_interval
65	1040		code4_IR_carrier_on array [0-15]
66	1056		code4_IR_carrier_on array [16-31]
67	1072		code4_IR_carrier_on array [32-47]
68	1088		code4_IR_carrier_on array [48-63]
69	1104		code4_IR_carrier_on array [64-79]
70	1120		code4_IR_carrier_on array [80-95]
71	1136		code4_IR_carrier_on array [96-111]
72	1152		code4_IR_carrier_off array [0-15]
73	1168		code4_IR_carrier_off array [16-31]
74	1184		code4_IR_carrier_off array [32-47]
75	1200		code4_IR_carrier_off array [48-63]
76	1216		code4_IR_carrier_off array [64-79]
77	1232		code4_IR_carrier_off array [80-95]
78	1248		code4_IR_carrier_off array [96-111]
79	1264
80	1280	code_5_IR_remote	code5_IR_carrier_freg_and_unit_interval
81	1296		code5_IR_carrier_on array [0-15]
82	1312		code5_IR_carrier_on array [16-31]
83	1328		code5_IR_carrier_on array [32-47]
84	1344		code5_IR_carrier_on array [48-63]
85	1360		code5_IR_carrier_on array [64-79]
86	1376		code5_IR_carrier_on array [80-95]
87	1392		code5_IR_carrier_on array [96-111]
88	1408		code5_IR_carrier_off array [0-15]
89	1424		code5_IR_carrier_off array [16-31]
90	1440		code5_IR_carrier_off array [32-47]
91	1456		code5_IR_carrier_off array [48-63]
92	1472		code5_IR_carrier_off array [64-79]
93	1488		code5_IR_carrier_off array [80-95]
94	1504		code5_IR_carrier_off array [96-111]
95	1520
96	1536	code_6_IR_remote	code6_IR_carrier_freg_and_unit_interval
97	1552		code6_IR_carrier_on array [0-15]
98	1568		code6_IR_carrier_on array [16-31]
99	1584		code6_IR_carrier_on array [32-47]
100	1600		code6_IR_carrier_on array [48-63]
101	1616		code6_IR_carrier_on array [64-79]
102	1632		code6_IR_carrier_on array [80-95]
103	1648		code6_IR_carrier_on array [96-111]
104	1664		code6_IR_carrier_off array [0-15]
105	1680		code6_IR_carrier_off array [16-31]
106	1696		code6_IR_carrier_off array [32-47]
107	1712		code6_IR_carrier_off array [48-63]
108	1728		code6_IR_carrier_off array [64-79]
109	1744		code6_IR_carrier_off array [80-95]
110	1760		code6_IR_carrier_off array [96-111]
111	1776
112	1792	code_7_IR_remote	code7_IR_carrier_freg_and_unit_interval
113	1808		code7_IR_carrier_on array [0-15]
114	1824		code7_IR_carrier_on array [16-31]
115	1840		code7_IR_carrier_on array [32-47]
116	1856		code7_IR_carrier_on array [48-63]
117	1872		code7_IR_carrier_on array [64-79]
118	1888		code7_IR_carrier_on array [80-95]
119	1904		code7_IR_carrier_on array [96-111]
120	1920		code7_IR_carrier_off array [0-15]
121	1936		code7_IR_carrier_off array [16-31]
122	1952		code7_IR_carrier_off array [32-47]
123	1968		code7_IR_carrier_off array [48-63]
124	1984		code7_IR_carrier_off array [64-79]
125	2000		code7_IR_carrier_off array [80-95]
126	2016		code7_IR_carrier_off array [96-111]
127	2032

After defining this memory map I started to write a function that would take the measured and encoded data and store it in one of the 8 blocks that I defined in the memory map. Here is the function that writes data into the EEPROM. The writing is done row by row, so this function had to rearrange the input data in row format and then write each row in the corresponding memory block.

Function to write array into memory:

void storedata_in_eeprom (uint8 aval[224], uint8 freqcarrier, uint16 unit, uint16 unittrim, uint8 locationnumber)

{

/*EEPROM_Start();*/

/*cystatus eraseStatus;*/

cystatus writeStatus;

uint8 eepromlocation = locationnumber;

uint8 freqeeprom = freqcarrier;

uint8 unit_lower = (unit & 0xF);

uint8 unit_upper = (unit >> 8);

uint8 unittrim_lower = (unittrim & 0xF);

uint8 unittrim_upper = (unittrim >> 8);

uint8 row1_data[SIZEOF_EEPROM_ROW] = {freqeeprom, unit_lower, unit_upper, unittrim_lower, unittrim_upper, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u, 0u};

uint8 row2_data[SIZEOF_EEPROM_ROW] = {aval[0], aval[1], aval[2], aval[3], aval[4], aval[5], aval[6], aval[7], aval[8], aval[9], aval[10], aval[11], aval[12], aval[13], aval[14], aval[15]};

uint8 row3_data[SIZEOF_EEPROM_ROW] = {aval[16], aval[17], aval[18], aval[19], aval[20], aval[21], aval[22], aval[23], aval[24], aval[25], aval[26], aval[27], aval[28], aval[29], aval[30], aval[31]};

uint8 row4_data[SIZEOF_EEPROM_ROW] = {aval[32], aval[33], aval[34], aval[35], aval[36], aval[37], aval[38], aval[39], aval[40], aval[41], aval[42], aval[43], aval[44], aval[45], aval[46], aval[47]};

uint8 row5_data[SIZEOF_EEPROM_ROW] = {aval[48], aval[49], aval[50], aval[51], aval[52], aval[53], aval[54], aval[55], aval[56], aval[57], aval[58], aval[59], aval[60], aval[61], aval[62], aval[63]};

uint8 row6_data[SIZEOF_EEPROM_ROW] = {aval[64], aval[65], aval[66], aval[67], aval[68], aval[69], aval[70], aval[71], aval[72], aval[73], aval[74], aval[75], aval[76], aval[77], aval[78], aval[79]};

uint8 row7_data[SIZEOF_EEPROM_ROW] = {aval[80], aval[81], aval[82], aval[83], aval[84], aval[85], aval[86], aval[87], aval[88], aval[89], aval[90], aval[91], aval[92], aval[93], aval[94], aval[95]};

uint8 row8_data[SIZEOF_EEPROM_ROW] = {aval[96], aval[97], aval[98], aval[99], aval[100], aval[101], aval[102], aval[103], aval[104], aval[105], aval[106], aval[107], aval[108], aval[109], aval[110], aval[111]};

uint8 row9_data[SIZEOF_EEPROM_ROW] = {aval[112], aval[113], aval[114], aval[115], aval[116], aval[117], aval[118], aval[119], aval[120], aval[121], aval[122], aval[123], aval[124], aval[125], aval[126], aval[127]};

uint8 row10_data[SIZEOF_EEPROM_ROW] = {aval[128], aval[129], aval[130], aval[131], aval[132], aval[133], aval[134], aval[135], aval[136], aval[137], aval[138], aval[139], aval[140], aval[141], aval[142], aval[143]};

uint8 row11_data[SIZEOF_EEPROM_ROW] = {aval[144], aval[145], aval[146], aval[147], aval[148], aval[149], aval[150], aval[151], aval[152], aval[153], aval[154], aval[155], aval[156], aval[157], aval[158], aval[159]};

uint8 row12_data[SIZEOF_EEPROM_ROW] = {aval[160], aval[161], aval[162], aval[163], aval[164], aval[165], aval[166], aval[167], aval[168], aval[169], aval[170], aval[171], aval[172], aval[173], aval[174], aval[175]};

uint8 row13_data[SIZEOF_EEPROM_ROW] = {aval[176], aval[177], aval[178], aval[179], aval[180], aval[181], aval[182], aval[183], aval[184], aval[185], aval[186], aval[187], aval[188], aval[189], aval[190], aval[191]};

uint8 row14_data[SIZEOF_EEPROM_ROW] = {aval[192], aval[193], aval[194], aval[195], aval[196], aval[197], aval[198], aval[199], aval[200], aval[201], aval[202], aval[203], aval[204], aval[205], aval[206], aval[207]};

uint8 row15_data[SIZEOF_EEPROM_ROW] = {aval[208], aval[209], aval[210], aval[211], aval[212], aval[213], aval[214], aval[215], aval[216], aval[217], aval[218], aval[219], aval[220], aval[221], aval[222], aval[223]};

uint8 rownumber = 0;

if(eepromlocation == 0) rownumber = 0u ;

if(eepromlocation == 1) rownumber = 16u ;

if(eepromlocation == 2) rownumber = 32u;

if(eepromlocation == 3) rownumber = 48u;

if(eepromlocation == 4) rownumber = 64u;

if(eepromlocation == 5) rownumber = 80u;

if(eepromlocation == 6) rownumber = 96u;

if(eepromlocation == 7) rownumber = 112u;

/* Get the die temp. */

if(CySetTemp() == CYRET_SUCCESS)

{

/* Write TestData1 to EEPROM row 0 */

writeStatus = EEPROM_Write(row1_data, rownumber);

writeStatus = EEPROM_Write(row2_data, rownumber+1u);

writeStatus = EEPROM_Write(row3_data, rownumber+2u);

writeStatus = EEPROM_Write(row4_data, rownumber+3u);

writeStatus = EEPROM_Write(row5_data, rownumber+4u);

writeStatus = EEPROM_Write(row6_data, rownumber+5u);

writeStatus = EEPROM_Write(row7_data, rownumber+6u);

writeStatus = EEPROM_Write(row8_data, rownumber+7u);

writeStatus = EEPROM_Write(row9_data, rownumber+8u);

writeStatus = EEPROM_Write(row10_data, rownumber+9u);

writeStatus = EEPROM_Write(row11_data, rownumber+10u);

writeStatus = EEPROM_Write(row12_data, rownumber+11u);

writeStatus = EEPROM_Write(row13_data, rownumber+12u);

writeStatus = EEPROM_Write(row14_data, rownumber+13u);

writeStatus = EEPROM_Write(row15_data, rownumber+14u);

}

/*EEPROM_Stop();*/

}

/* end of function "storedata_in_eeprom" */

After writing this function I looked into how to read back the values. Reading is different than writing; reading can be done at byte level, and I need to read back the infrared carrier frequency, the unit interval used in data encoding (as I showed in the previous blog) and the array of 224 locations that contains the encoded data. I decided to write three functions, one for each of this type of data.

Here is the function that reads the carrier frequency. Basically the function reads the entire first row and then extracts the value from the specific location in the row where the carrier frequency information has been stored. I could have read only the byte that stores that value, but I decided to read the entire row so that I can reuse this piece of code in the other functions.

/* function read frequency from one of the 8 code locations in eeprom */

uint8 read_frequency_from_eeprom (uint8 locationnumber)

{

reg8 * RegPointer;

RegPointer = (reg8 *)CYDEV_EE_BASE;

uint16 Index;

uint8 return_freq;

uint8 eepromlocation = locationnumber;

uint8 row_read[SIZEOF_EEPROM_ROW];

uint16 base_number;

if(eepromlocation == 0) base_number = 0u;/*rownumber = 0u ;*/

if(eepromlocation == 1) base_number = 256u;/*rownumber = 16u ;*/

if(eepromlocation == 2) base_number = 512u;/*rownumber = 32u;*/

if(eepromlocation == 3) base_number = 768u;/*rownumber = 48u;*/

if(eepromlocation == 4) base_number = 1024u;/*rownumber = 64u;*/

if(eepromlocation == 5) base_number = 1280u;/*rownumber = 80u;*/

if(eepromlocation == 6) base_number = 1536u;/*rownumber = 96u;*/

if(eepromlocation == 7) base_number = 1792u;/*rownumber = 112u;*/

/* Read Data */

RegPointer = (reg8 *) CYDEV_EE_BASE + base_number;

for(Index = 0u; Index < SIZEOF_EEPROM_ROW; Index++)

{

row_read[Index] = RegPointer[Index];

}

return_freq = row_read[0];

verfreq2 = return_freq;

return(return_freq);

}

Next, I wrote a function that reads the unit interval. The unit interval is a uint16 type variable, so it is stored in two locations of the first EEPROM row. The function reads these two locations as uint8 values and then combines them into a uint16 variable that is then returned. Here is the function code:

/* function read unit interval from one of the 8 code locations in eeprom */

uint16 read_unitinterval_from_eeprom (uint8 locationnumber)

{

reg8 * RegPointer;

RegPointer = (reg8 *)CYDEV_EE_BASE;

uint16 Index;

uint16 return_unit;

uint8 unit_lower;

uint8 unit_upper;