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","type":"text"}]},{"type":"paragraph","content":[{"text":"This circuit measures:","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The ","type":"text"},{"text":"voltage ","type":"text","marks":[{"type":"strong"}]},{"text":"of each cell","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"The ","type":"text"},{"text":"current ","type":"text","marks":[{"type":"strong"}]},{"text":"delivered by the group","type":"text"}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"This is done by forcing the battery to deliver current through a resistor with a tiny resistance. 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(","type":"text"},{"text":"REF_SEL","type":"text","marks":[{"type":"code"}]},{"text":"=1), representing the cell current for cells 1-6, as measured by a 1-milliohm shunt","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"PA5","type":"text","marks":[{"type":"strong"}]},{"text":": ","type":"text"},{"text":"VCOUT1_FILT","type":"text","marks":[{"type":"code"}]},{"text":", receives 1.47-1.53 V (","type":"text"},{"text":"REF_SEL","type":"text","marks":[{"type":"code"}]},{"text":"=0) / 2.94-3.06 V (","type":"text"},{"text":"REF_SEL","type":"text","marks":[{"type":"code"}]},{"text":"=1), representing the cell voltages for cells 1-6","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"PB0","type":"text","marks":[{"type":"strong"}]},{"text":": ","type":"text"},{"text":"ADC1_FILT","type":"text","marks":[{"type":"code"}]},{"text":", receives 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Neither the DroneCAN website nor the Libcanard repo has beginner-friendly tutorials. YouTube videos also won’t help directly","type":"text"}]}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"Tasks Break Down:","type":"text"}]},{"type":"heading","attrs":{"level":2},"content":[{"type":"emoji","attrs":{"id":"2705","text":"✅","shortName":":white_check_mark:"}},{"text":" Action Items","type":"text"}]},{"type":"taskList","attrs":{"localId":""},"content":[{"type":"taskItem","attrs":{"state":"TODO","localId":"402"},"content":[{"text":"Initialize the Battery Monitoring Circuit using I","type":"text"},{"text":"2","type":"text","marks":[{"type":"subsup","attrs":{"type":"sup"}}]},{"text":"C","type":"text"}]},{"type":"taskItem","attrs":{"state":"TODO","localId":"408"},"content":[{"text":"Read battery data using the specified ports","type":"text"}]},{"type":"taskItem","attrs":{"state":"TODO","localId":"409"},"content":[{"text":"Fix suspected I","type":"text"},{"text":"2","type":"text","marks":[{"type":"subsup","attrs":{"type":"sup"}}]},{"text":"C timing issue during communication to the BMC","type":"text"}]}]},{"type":"heading","attrs":{"level":2},"content":[{"type":"emoji","attrs":{"id":"1f6a9","text":"\\uD83D\\uDEA9","shortName":":triangular_flag_on_post:"}},{"text":" Milestones","type":"text"}]},{"type":"taskList","attrs":{"localId":""},"content":[{"type":"taskItem","attrs":{"state":"TODO","localId":"403"},"content":[{"text":"Understand project specifications","type":"text"}]},{"type":"taskItem","attrs":{"state":"TODO","localId":"404"},"content":[{"text":"Understand the I","type":"text"},{"text":"2","type":"text","marks":[{"type":"subsup","attrs":{"type":"sup"}}]},{"text":"C protocol","type":"text"}]},{"type":"taskItem","attrs":{"state":"TODO","localId":"405"},"content":[{"text":"Understand the CAN protocol","type":"text"}]},{"type":"taskItem","attrs":{"state":"TODO","localId":"406"},"content":[{"text":"Understand DroneCAN","type":"text"}]},{"type":"taskItem","attrs":{"state":"TODO","localId":"407"},"content":[{"text":"etc.","type":"text"}]}]},{"type":"heading","attrs":{"level":1},"content":[{"text":"Open Questions","type":"text","marks":[{"type":"strong"}]}]},{"type":"bulletList","content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"How should the MCU beacon itself to the FC (i.e. so that the FC is aware that the MCU on the power module is there)?","type":"text"}]}]},{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"What should be sent over CAN? 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","type":"text"}]},{"type":"paragraph","content":[{"text":"To put this into jargon, since there are 32 numbers between 0 and 31, and 32 is 2 to the 5th power, we say that the ADC’s resolution is 5 bits, and it counted a value of 16.","type":"text"}]},{"type":"panel","attrs":{"panelType":"note"},"content":[{"type":"paragraph","content":[{"text":"An ADC’s ","type":"text"},{"text":"resolution ","type":"text","marks":[{"type":"strong"}]},{"text":"is the number of bits that are used to represent its outputs,","type":"text"},{"type":"hardBreak"},{"text":"and its ","type":"text"},{"text":"count ","type":"text","marks":[{"type":"strong"}]},{"text":"is the number it’s currently giving.","type":"text"}]},{"type":"paragraph","content":[{"text":"Higher resolution","type":"text","marks":[{"type":"underline"}]},{"text":" means ","type":"text"},{"text":"more precise","type":"text","marks":[{"type":"underline"}]},{"text":" voltage measurement.","type":"text"}]}]},{"type":"heading","attrs":{"level":3},"content":[{"text":"Battery Monitoring Circuit","type":"text"}]},{"type":"paragraph","content":[{"text":"Datasheet: ","type":"text"},{"type":"inlineCard","attrs":{"url":"https://www.ti.com/product/BQ76925?qgpn=bq76925#software-development"}},{"text":" ","type":"text"}]},{"type":"heading","attrs":{"level":4},"content":[{"text":"Addressing","type":"text","marks":[{"type":"strong"}]}]},{"type":"paragraph","content":[{"text":"All I","type":"text"},{"text":"2","type":"text","marks":[{"type":"subsup","attrs":{"type":"sup"}}]},{"text":"C addresses are calculated using the formula ","type":"text"}]},{"type":"codeBlock","attrs":{"language":"c"},"content":[{"text":"ADDRESS = 0x20 + REG_ADDR","type":"text"}]},{"type":"paragraph","content":[{"text":"Where ","type":"text"},{"text":"ADDRESS","type":"text","marks":[{"type":"code"}]},{"text":" is the ","type":"text"},{"text":"real address","type":"text","marks":[{"type":"strong"}]},{"text":" to read/write to, and ","type":"text"},{"text":"REG_ADDR","type":"text","marks":[{"type":"code"}]},{"text":" is the ","type":"text"},{"text":"register address","type":"text","marks":[{"type":"strong"}]},{"text":" mentioned on the datasheet, from ","type":"text"},{"text":"0x00","type":"text","marks":[{"type":"code"}]},{"text":" to ","type":"text"},{"text":"0x1F","type":"text","marks":[{"type":"code"}]},{"text":".","type":"text"},{"type":"hardBreak"},{"text":"Remember this distinction","type":"text","marks":[{"type":"underline"},{"type":"strong"}]},{"text":" between the ","type":"text"},{"text":"real ","type":"text","marks":[{"type":"em"}]},{"text":"and ","type":"text"},{"text":"register ","type":"text","marks":[{"type":"em"}]},{"text":"addresses. All I","type":"text"},{"text":"2","type":"text","marks":[{"type":"subsup","attrs":{"type":"sup"}}]},{"text":"C addresses you see after this point will be ","type":"text"},{"text":"register addresses","type":"text","marks":[{"type":"em"}]},{"text":".","type":"text"}]},{"type":"paragraph","marks":[{"type":"alignment","attrs":{"align":"end"}}],"content":[{"text":"Source: Datasheet, ","type":"text"},{"text":"8.5.1.1 I","type":"text","marks":[{"type":"em"}]},{"text":"2","type":"text","marks":[{"type":"subsup","attrs":{"type":"sup"}},{"type":"em"}]},{"text":"C Addressing","type":"text","marks":[{"type":"em"}]}]},{"type":"heading","attrs":{"level":4},"content":[{"text":"Selecting the cell for the ","type":"text","marks":[{"type":"strong"}]},{"text":"VCOUT","type":"text","marks":[{"type":"code"}]},{"text":" ","type":"text"},{"text":"pin","type":"text","marks":[{"type":"strong"}]}]},{"type":"paragraph","content":[{"text":"To select the cell to measure the voltage of:","type":"text"}]},{"type":"codeBlock","attrs":{"language":"c"},"content":[{"text":"// Write to the register address:\nREG_ADDR = 0x01\n\n// With data:\nDATA = 0x10 + CELL","type":"text"}]},{"type":"paragraph","content":[{"text":"Where ","type":"text"},{"text":"CELL","type":"text","marks":[{"type":"code"}]},{"text":" is the cell number. ","type":"text"},{"text":"CELL=0x0","type":"text","marks":[{"type":"code"}]},{"text":" refers to cell 1, ","type":"text"},{"text":"CELL=0x1","type":"text","marks":[{"type":"code"}]},{"text":" refers to cell 2, and so on, up to ","type":"text"},{"text":"CELL=0x5","type":"text","marks":[{"type":"code"}]},{"text":"referring to cell 6.","type":"text"}]},{"type":"paragraph","marks":[{"type":"alignment","attrs":{"align":"end"}}],"content":[{"text":"Source: Datasheet,","type":"text"},{"text":" 8.6.1 Register Descriptions (Tables 6 to 8)","type":"text","marks":[{"type":"em"}]}]},{"type":"heading","attrs":{"level":4},"content":[{"text":"Reference voltage selection","type":"text","marks":[{"type":"strong"}]}]},{"type":"codeBlock","attrs":{"language":"c"},"content":[{"text":"// Write to the register address:\nREG_ADDR = 0x04\n\n// With data:\nDATA = REF_SEL","type":"text"}]},{"type":"paragraph","content":[{"text":"Where ","type":"text"},{"text":"REF_SEL","type":"text","marks":[{"type":"code"}]},{"text":" can be set to ","type":"text"},{"text":"0","type":"text","marks":[{"type":"code"}]},{"text":" or ","type":"text"},{"text":"1","type":"text","marks":[{"type":"code"}]},{"text":", with the following effects on the BMC pins:","type":"text"}]},{"type":"paragraph","marks":[{"type":"alignment","attrs":{"align":"center"}}],"content":[{"text":"Table 14. 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To do that, add ","type":"text"},{"text":"0x80","type":"text","marks":[{"type":"code"}]},{"text":" to ","type":"text"},{"text":"DATA","type":"text","marks":[{"type":"code"}]},{"text":" above.","type":"text"}]},{"type":"paragraph","content":[{"text":"We haven’t decided whether we want CRC though, so right now we’ll use the default option… which is “disabled“.","type":"text"}]}]},{"type":"paragraph","marks":[{"type":"alignment","attrs":{"align":"end"}}],"content":[{"text":"Source: Datasheet,","type":"text"},{"text":" 8.6.1 Register Descriptions (Tables 13 and 14)","type":"text","marks":[{"type":"em"}]}]},{"type":"heading","attrs":{"level":4},"content":[{"text":"Cell Voltage Monitoring","type":"text","marks":[{"type":"strong"}]}]},{"type":"codeBlock","attrs":{"language":"c"},"content":[{"text":"// The voltage of the currently selected cell, VCn (where 'n' is the cell number),\n// is calculated with the following formula:\nVCn = ((VCOUT * GC_VREF + OC_VCOUT) / G_VCOUT) * (1 + GC_VCOUT)\n\n// Where:\nVCOUT = ADC_count / Full_scale_count * VREF_NOMINAL // This is the voltage of the VCOUT pin, as measured by the MCU\nGC_VCOUT = ((VCn_GC_4 << 4) + VCn_GAIN_CORR) * 1E-3\nOC_VCOUT = ((VCn_OC_4 << 4) + VCn_OFFSET_CORR) * 1E-3\nGC_VREF = (1 + ((VREF_GC_4 << 4) + VREF_GAIN_CORR) * 1E-3) \n + (((VREF_OC_5 << 5) + (VREF_OC_4 << 4) + VREF_OFFSET_CORR) * 1E-3)/VREF_NOMINAL","type":"text"}]},{"type":"paragraph","content":[{"text":"Several values can be accessed through the I","type":"text"},{"text":"2","type":"text","marks":[{"type":"subsup","attrs":{"type":"sup"}}]},{"text":"C interface:","type":"text"}]},{"type":"expand","attrs":{"title":"VCn_GC_4, where n is the cell 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Make sure you don’t miss anything!","type":"text"}]}]},{"type":"paragraph","content":[{"text":"Follow the steps below, in that order:","type":"text"}]},{"type":"heading","attrs":{"level":5},"content":[{"text":"Step One","type":"text","marks":[{"type":"backgroundColor","attrs":{"color":"#dcdfe4"}}]}]},{"type":"paragraph","content":[{"text":"Configure the ","type":"text"},{"text":"range","type":"text","marks":[{"type":"strong"}]},{"text":" and ","type":"text"},{"text":"precision","type":"text","marks":[{"type":"strong"}]},{"text":" of the current measurement, by:","type":"text"}]},{"type":"orderedList","attrs":{"order":1},"content":[{"type":"listItem","content":[{"type":"paragraph","content":[{"text":"Let the BMC know the reference voltage of the ADC by ","type":"text"},{"text":"setting REF_SEL","type":"text","marks":[{"type":"link","attrs":{"href":"#ref-sel"}}]},{"text":". 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For example, a precision of ","type":"text"},{"text":"0.5","type":"text","marks":[{"type":"code"}]},{"text":" means that the current measurement will only be ","type":"text"},{"text":"integer multiples","type":"text","marks":[{"type":"strong"}]},{"text":" of ","type":"text"},{"text":"0.5","type":"text","marks":[{"type":"code"}]},{"text":".","type":"text"}]}]}]},{"type":"paragraph","content":[{"text":"The effects of setting different values to ","type":"text"},{"text":"REF_SEL","type":"text","marks":[{"type":"code"}]},{"text":" and ","type":"text"},{"text":"I_GAIN","type":"text","marks":[{"type":"code"}]},{"text":" is shown in the table 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