Changes for page Sensor Module

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...	...	@@ -24,7 +24,7 @@
24	24
25	25	The Sensor module is designed to measure any extra analog signals rear of the firewall. For AR26, the module is designed to measure two suspension displacement sensors, two oil temperature, four water pressure, four water temperature, and one air temperature sensor. All of the measurements are then transmitted to a CAN network, which there are two of.
26	26
27		-= Design =
	27	+= Wiring Diagram =
28	28
29	29	In the following section, how the sensor module is connected will be covered. The connector for the sensor module is a [[High-Density d'sub-44>>https://www.te.com/en/product-2311770-1.html]] which is directly solderen onto the circuit board. The plug needed for this system is the [[204517-3>>doc:Sandbox.TestPage3]], which uses crimps instead of solder cups which is common for the dsub connectors
30	30
...	...	@@ -66,49 +66,6 @@
66	66	|(% style="width:71px" %)14|(% style="width:164px" %)CAN High 1|(% style="width:124px" %)CAN|(% style="width:70px" %)29|(% style="width:218px" %)CAN Low 2|(% style="width:58px" %)CAN|(% style="width:32px" %)44|(% style="width:192px" %)Main Power|(% style="width:90px" %)+24V
67	67	|(% style="width:71px" %)15|(% style="width:164px" %)CAN Low 1|(% style="width:124px" %)CAN|(% style="width:70px" %)30|(% style="width:218px" %)CAN High 2|(% style="width:58px" %)CAN|(% style="width:32px" %) |(% style="width:192px" %) |(% style="width:90px" %)
68	68
69		-== Microcontroller Pinout ==
70		-
71		-The sensor module uses a microcontroller to measure and calculate the values for the analog signals. The microcontroller used in this system is the [[STM32G491RET6>>doc:.https\:www\.st\.comenmicrocontrollers-microprocessorsstm32g491re\.html.WebHome]]
72		-
73		-(% style="width:793.6px" %)
74		-|=(% style="width: 96px;" %)Physical Pin|=(% style="width: 102px;" %)Electrical Pin|=(% style="width: 593px;" %)Description
75		-|(% style="width:96px" %)1|(% style="width:102px" %)VBAT|(% style="width:593px" %)Power source from a backup battery if a RTC would be used (Connected to +3V3 in this case)
76		-|(% style="width:96px" %)5|(% style="width:102px" %)OSC_IN|(% style="width:593px" %)Clock input (8MHz oscillator)
77		-|(% style="width:96px" %)7|(% style="width:102px" %)NRST|(% style="width:593px" %)Negative reset which can be connected to a button (Connected to +3V3)
78		-|(% style="width:96px" %)9|(% style="width:102px" %)PC1|(% style="width:593px" %)Analog signal: Cooling pressure sensor number 2
79		-|(% style="width:96px" %)10|(% style="width:102px" %)PC2|(% style="width:593px" %)Analog signal: Cooling temperature sensor number 2
80		-|(% style="width:96px" %)11|(% style="width:102px" %)PC3|(% style="width:593px" %)Analog signal: Cooling pressure sensor number 4
81		-|(% style="width:96px" %)12|(% style="width:102px" %)PA0|(% style="width:593px" %)Analog signal: Cooling temperature sensor number 4
82		-|(% style="width:96px" %)13|(% style="width:102px" %)PA1|(% style="width:593px" %)Analog signal: Oil temperature sensor right
83		-|(% style="width:96px" %)14|(% style="width:102px" %)PA2|(% style="width:593px" %)Analog signal: Air temperature sensor
84		-|(% style="width:96px" %)15|(% style="width:102px" %)VSS|(% style="width:593px" %)Voltage source: Ground
85		-|(% style="width:96px" %)16|(% style="width:102px" %)VDD|(% style="width:593px" %)Voltage source: Power (+3V3)
86		-|(% style="width:96px" %)17|(% style="width:102px" %)PA3|(% style="width:593px" %)Analog signal: Cooling pressure sensor number 1
87		-|(% style="width:96px" %)18|(% style="width:102px" %)PA4|(% style="width:593px" %)Analog signal: Cooling temperature sensor number 1
88		-|(% style="width:96px" %)19|(% style="width:102px" %)PA5|(% style="width:593px" %)Analog signal: Cooling pressure sensor number 3
89		-|(% style="width:96px" %)20|(% style="width:102px" %)PA6|(% style="width:593px" %)Analog signal: Cooling temperature sensor number 3
90		-|(% style="width:96px" %)21|(% style="width:102px" %)PA7|(% style="width:593px" %)Analog signal: Oil temperature sensor left
91		-|(% style="width:96px" %)22|(% style="width:102px" %)PC4|(% style="width:593px" %)Analog signal: Suspension displacement sensor right
92		-|(% style="width:96px" %)23|(% style="width:102px" %)PC5|(% style="width:593px" %)Analog signal: Suspension displacement sensor left
93		-|(% style="width:96px" %)27|(% style="width:102px" %)VSSA|(% style="width:593px" %)Voltage source: Ground
94		-|(% style="width:96px" %)28|(% style="width:102px" %)VREF+|(% style="width:593px" %)Voltage reference (connected to +3V3)
95		-|(% style="width:96px" %)29|(% style="width:102px" %)VDDA|(% style="width:593px" %)Voltage source: Power (+3V3)
96		-|(% style="width:96px" %)31|(% style="width:102px" %)VSS|(% style="width:593px" %)Voltage source: Ground
97		-|(% style="width:96px" %)32|(% style="width:102px" %)VDD|(% style="width:593px" %)Voltage source: Power (+3V3)
98		-|(% style="width:96px" %)34|(% style="width:102px" %)PB12|(% style="width:593px" %)CAN-BUS 2: Rxd
99		-|(% style="width:96px" %)35|(% style="width:102px" %)PB13|(% style="width:593px" %)CAN-BUS 2: Txd
100		-|(% style="width:96px" %)38|(% style="width:102px" %)PC6|(% style="width:593px" %)Signal Output: Blue status LED
101		-|(% style="width:96px" %)45|(% style="width:102px" %)PA11|(% style="width:593px" %)CAN-BUS 2: Rxd
102		-|(% style="width:96px" %)46|(% style="width:102px" %)PA12|(% style="width:593px" %)CAN-BUS 2: Txd
103		-|(% style="width:96px" %)47|(% style="width:102px" %)VSS|(% style="width:593px" %)Voltage source: Ground
104		-|(% style="width:96px" %)48|(% style="width:102px" %)VDD|(% style="width:593px" %)Voltage source: Power (+3V3)
105		-|(% style="width:96px" %)49|(% style="width:102px" %)PA13|(% style="width:593px" %)Programming Pins: SWDIO
106		-|(% style="width:96px" %)50|(% style="width:102px" %)PA14|(% style="width:593px" %)Programming Pins: SWCLK
107		-|(% style="width:96px" %)63|(% style="width:102px" %)VSS|(% style="width:593px" %)Voltage source: Ground
108		-|(% style="width:96px" %)64|(% style="width:102px" %)VDD|(% style="width:593px" %)Voltage source: Power (+3V3)
109		-
110		-
111		-
112	112	== Air Temperature Sensor ==
113	113
114	114	The air temperature sensor will be used to have a dynamic reference setpoint for the cooling system. This could reduce the current draw from the low voltage system compared to having a fixed reference point. This is because the regulator will not try to cool the water to a temperature lower than the ambient temperature. The sensor works as a resistor which varies depending on its temperature. Where in this case, the resistance lowers when the temperature increases (NTC). To make the microcontroller able to measure the changes in resistance, the thermistor is put into a voltage divider circuit.
...	...	@@ -129,10 +129,10 @@
129	129
130	130	Where:
131	131
132		-* {{mathjax}}\(R_f\){{/mathjax}}= The upper resistor in the voltage divider which stays fixed, which in this case is 4.7k {{mathjax}}\(\Omega\){{/mathjax}}
133		-* {{mathjax}}\(V_{out}\){{/mathjax}}= The voltage over the thermistor, and the voltage that the microcontroller will measure.
134		-* {{mathjax}}\(V_{in}\){{/mathjax}}= The supply voltage of the voltage divider, which in this case is a constant 3.3 {{mathjax}}\(V\){{/mathjax}}
135		-* {{mathjax}}\(R_T\){{/mathjax}}= Resistance of the thermistor
	89	+* {{mathjax}}\(R_f\){{/mathjax}} = The upper resistor in the voltage divider which stays fixed, which in this case is 4.7k {{mathjax}}\(\Omega\){{/mathjax}}
	90	+* {{mathjax}}\(V_{out}\){{/mathjax}} = The voltage over the thermistor, and the voltage that the microcontroller will measure.
	91	+* {{mathjax}}\(V_{in}\){{/mathjax}} = The supply voltage of the voltage divider, which in this case is a constant 3.3 {{mathjax}}\(V\){{/mathjax}}
	92	+* {{mathjax}}\(R_T\){{/mathjax}} = Resistance of the thermistor
136	136
137	137	Knowing this, the resistance of the thermistor can be added into the following equation. This will determine the temperature of the thermistor based on the known resistance and the beta value of the thermistor.
138	138
...	...	@@ -147,10 +147,10 @@
147	147
148	148	where:
149	149
150		-* {{mathjax}}\(\beta\){{/mathjax}}= material constant that defines the steepness of its resistance-temperature curve between two temperature points, usually 25/85 degrees celsius. In this case it is 3694 //**K.**//
151		-* {{mathjax}}\(T_0\){{/mathjax}}= The test temperature at which the thermistor is 10k {{mathjax}}\(\Omega\){{/mathjax}}, which in this case is 25 degrees celsius.
152		-* {{mathjax}}\(R_0\){{/mathjax}}= The resistance of the thermistor when it is 25 degrees celsius.
153		-* {{mathjax}}\(R_T\){{/mathjax}}= The live resistance of the thermistor.
	107	+* {{mathjax}}\(\beta\){{/mathjax}} = material constant that defines the steepness of its resistance-temperature curve between two temperature points, usually 25/85 degrees celsius. In this case it is 3694 //**K.**//
	108	+* {{mathjax}}\(T_0\){{/mathjax}} = The test temperature at which the thermistor is 10k {{mathjax}}\(\Omega\){{/mathjax}}, which in this case is 25 degrees celsius.
	109	+* {{mathjax}}\(R_0\){{/mathjax}} = The resistance of the thermistor when it is 25 degrees celsius.
	110	+* {{mathjax}}\(R_T\){{/mathjax}} = The current resistance of the thermistor.
154	154
155	155	=== Filtering ===
156	156
...	...	@@ -167,9 +167,9 @@
167	167
168	168	Where:
169	169
170		-* {{mathjax}}\(F_c\){{/mathjax}}= Cut-off frequency of the filter. Any noise with a frequency above this will be filtered out.
171		-* {{mathjax}}\(R\){{/mathjax}}= Resistance of the resistor in low-pass filter.
172		-* {{mathjax}}\(C\){{/mathjax}}= Capacitance of the capacitor in the low-pass filter.
	127	+* {{mathjax}}\(F_c\){{/mathjax}} = Cut-off frequency of the filter. Any noise with a frequency above this will be filtered out.
	128	+* {{mathjax}}\(R\){{/mathjax}} = Resistance of the resistor in low-pass filter.
	129	+* {{mathjax}}\(C\){{/mathjax}} = Capacitance of the capacitor in the low-pass filter.
173	173
174	174	Using a resistor with 1k {{mathjax}}\(\Omega\){{/mathjax}} and a capacitor with 100 **nF **in capacitance, the cut-off frequency will be 1592 **Hz.**
175	175
...	...	@@ -196,9 +196,9 @@
196	196
197	197	where:
198	198
199		-* {{mathjax}}\(x\){{/mathjax}}= The mechanical placement excluding the dead length (178mm).
200		-* {{mathjax}}\(V_s\){{/mathjax}}= The supply voltage of the linear potentiometer, in this case it is 3.3 {{mathjax}}\(V\){{/mathjax}}.
201		-* {{mathjax}}\(V_{out}\){{/mathjax}}= The output voltage of the linear potentiometer. ranging from 0.033{{mathjax}}\(V\){{/mathjax}} to 3.267{{mathjax}}\(V\){{/mathjax}}.
	156	+* {{mathjax}}\(x\){{/mathjax}} = The mechanical placement excluding the dead length (178mm).
	157	+* {{mathjax}}\(V_s\){{/mathjax}} = The supply voltage of the linear potentiometer, in this case it is 3.3 {{mathjax}}\(V\){{/mathjax}}.
	158	+* {{mathjax}}\(V_{out}\){{/mathjax}} = The output voltage of the linear potentiometer. ranging from 0.033{{mathjax}}\(V\){{/mathjax}} to 3.267{{mathjax}}\(V\){{/mathjax}}.
202	202
203	203	=== Filtering ===
204	204
...	...	@@ -208,7 +208,7 @@
208	208
209	209	The gearbox Temperature Sensor for AR26 will be the [[GAG10K3976B1>>https://www.te.com/en/product-GAG10K3976B1.html]], a NTC temperature probe which will be installed into a generic M5 bolt which is mounted on the upright in the wheel assembly. The thermistor will be connected in a voltage divider configuration where the thermistor is in the lower position so that the voltage lowers when the temperature increases.
210	210
211		-[[image:Oil_Temp_schematic.png||height="208" width="486"]]
	168	+[[image:Oil_Temp_schematic.png||height="271" width="632"]]
212	212
213	213	Knowing the beta constant of the thermistor, the equation for the temperature based on the voltage measured by the ADC inside microcontroller can be derived.
214	214
...	...	@@ -223,10 +223,10 @@
223	223
224	224	Where:
225	225
226		-* {{mathjax}}\(R_f\){{/mathjax}}= The upper resistor in the voltage divider which stays fixed, which in this case is 1k {{mathjax}}\(\Omega\){{/mathjax}}
227		-* {{mathjax}}\(V_{out}\){{/mathjax}}= The voltage over the thermistor, and the voltage that the microcontroller will measure.
228		-* {{mathjax}}\(V_{in}\){{/mathjax}}= The supply voltage of the voltage divider, which in this case is a constant 3.3 {{mathjax}}\(V\){{/mathjax}}
229		-* {{mathjax}}\(R_T\){{/mathjax}}= Resistance of the thermistor
	183	+* {{mathjax}}\(R_f\){{/mathjax}} = The upper resistor in the voltage divider which stays fixed, which in this case is 1k {{mathjax}}\(\Omega\){{/mathjax}}
	184	+* {{mathjax}}\(V_{out}\){{/mathjax}} = The voltage over the thermistor, and the voltage that the microcontroller will measure.
	185	+* {{mathjax}}\(V_{in}\){{/mathjax}} = The supply voltage of the voltage divider, which in this case is a constant 3.3 {{mathjax}}\(V\){{/mathjax}}
	186	+* {{mathjax}}\(R_T\){{/mathjax}} = Resistance of the thermistor
230	230
231	231	Knowing this, the resistance of the thermistor can be added into the following equation. This will determine the temperature of the thermistor based on the known resistance and the beta value of the thermistor.
232	232
...	...	@@ -241,21 +241,7 @@
241	241
242	242	where:
243	243
244		-* {{mathjax}}\(\beta\){{/mathjax}}= material constant that defines the steepness of its resistance-temperature curve between two temperature points, usually 25/85 degrees celsius. In this case it is 3976 //**K.**//
245		-* {{mathjax}}\(T_0\){{/mathjax}}= The test temperature at which the thermistor is 10k {{mathjax}}\(\Omega\){{/mathjax}}, which in this case is 25 degrees celsius.
246		-* {{mathjax}}\(R_0\){{/mathjax}}= The resistance of the thermistor when it is 25 degrees celsius.
247		-* {{mathjax}}\(R_T\){{/mathjax}}= The live resistance of the thermistor.
248		-
249		-=== Filtering ===
250		-
251		-The sensors output latency can be expected to be a lot shorter than the oil temperature sensor as the sensor is just a variable sensor based on placement. The limiting factor for the system which uses this information is the CAN-BUS messages from the inverters which send the information each 6.25 milliseconds. This means that the cut-off frequency cannot be any lower than 160 Hz, which will make the same type of low pass filter from the oil temperature sensor acceptable with a cut-off frequency of 1591 Hz.
252		-
253		-= Bill of Materials =
254		-
255		-== Circuit Board ==
256		-
257		-== Wiring Harness ==
258		-
259		-== Sensors ==
260		-
261		-
	201	+* {{mathjax}}\(\beta\){{/mathjax}} = material constant that defines the steepness of its resistance-temperature curve between two temperature points, usually 25/85 degrees celsius. In this case it is 3976 //**K.**//
	202	+* {{mathjax}}\(T_0\){{/mathjax}} = The test temperature at which the thermistor is 10k {{mathjax}}\(\Omega\){{/mathjax}}, which in this case is 25 degrees celsius.
	203	+* {{mathjax}}\(R_0\){{/mathjax}} = The resistance of the thermistor when it is 25 degrees celsius.
	204	+* {{mathjax}}\(R_T\){{/mathjax}} = The current resistance of the thermistor.