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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?iso-8859-1?Q?wGqKj9qbm3Y33w/zdtDdUW8hA8wsCM1WOPmiclCw7tqvAZdwEFNOYGv3CF?= =?iso-8859-1?Q?at7V+NXWRJfA0E2hHGpCJ0ZBmTYn1ZksGwe/5XuFYdbYjjTIGSQovTExpU?= =?iso-8859-1?Q?DuVPXgxRpYb9qiRMGoMh937E8VnPgdOlp7zQSvovW8TXPZmg732kXlVJyP?= =?iso-8859-1?Q?8mOtrlyfNwf1R3AJvZ3ZVa4hekaETHERAkfXGFZL8a0I7KEvZVLPjtPimr?= =?iso-8859-1?Q?MkmcE6UlAoqsWMz3NxoWfp0v3KxQ0C5hYqgIWK4O1sLTC1FlFggLii0blW?= =?iso-8859-1?Q?HARf82RD7MfGnhmprW6fvywbZfYcWiL0AW87xoKqY9RbnxC7++o4MsOLj2?= =?iso-8859-1?Q?YOox45kg3v5+vrBrPi5AGYo8SWLyh887gtMZ7057tnkfB5k6bdOcy/mQQN?= =?iso-8859-1?Q?yCootcaK3kCLDQn9WMTEe06zaMvTTsumqw3CDBCNarKxK8105FYs4NOuBr?= =?iso-8859-1?Q?Zm21OXF8xzeN3WzZ0O3ky2wRh13SEAMkhwSfHVsTaYTInI5XTT1rq9b/xR?= =?iso-8859-1?Q?RD3LgmtHXU0u/pbgss53aBbB/TPoCa/yjiC0tcU7EprREyjM7t6Kwm2/1l?= =?iso-8859-1?Q?5l9/256CcVlrm0wU3SK0B35uxBrzej+g0SA/XajNQ5xp9AwUbaWl6/voN9?= =?iso-8859-1?Q?Y31hVl47+Oc63BweKywMoyPnV4GDFacSwD7vQgOrgIJUBHbo+R1nzNciIt?= =?iso-8859-1?Q?fZBA1Q2CdIISPOozaDwHdkPcUnPCZbUweesxwgYYOKdgBTuOrr+3oRspe1?= =?iso-8859-1?Q?svTSeHiL8v+RM46H+zf6JQX5LVUpzGRjfito0apuhtwvQTUFz/ful3RDzB?= =?iso-8859-1?Q?VQTycnDxTtHl9whgX8ivjMprRIx0MMvq+Sk9kE+uZWOHlT3vUUiVaAlzGf?= =?iso-8859-1?Q?IBGqJbm95DSdIGg6P0nW2ubQ+X7zp2iIe4sJI8YqNoUPewQySKUBaZeSIF?= =?iso-8859-1?Q?I2YB4k/QWgV+arRQATsJjdD4mtFqz5bNxCYAuGmyYuEW7CkRw1vfEw4wfi?= =?iso-8859-1?Q?1ObyeYRn5rwg5iIg1x8lpXCYFpWA5VbFGwuhLR6I5BrnnAS+lxNOiCF3QO?= =?iso-8859-1?Q?4ULRasDeDa7X0AEca/AHtmCqJS+FB1vAnuBOiGyMG0pQC6B7jcMQiQUGK6?= =?iso-8859-1?Q?HKl0C7WTr0a+M2ypW+OoCVupMcHdL+zewO8rU84bEqOmu6oyf9mNR0O0wD?= =?iso-8859-1?Q?IJE1ErewWKj6Eqv2uyg1jyjSsUX5ZQUZklBgf4XNv64whlHSfiEMrEsw/T?= =?iso-8859-1?Q?NtTE1fXc6ACjtqt1dwTP+V9jCOBzPBYWZjyv2WzUhPeQSXYbK+ihghVX9W?= =?iso-8859-1?Q?8GL3p0z/lQEjfK8EeE3ybHZA+lxJO8RTDCv3kEJizwTKm6FQP6JEq4B3gT?= =?iso-8859-1?Q?G3vSE2FpzTqoSnYe86kdHfuOMNvdCNxPCWjxALNVQulb4OOI6GzDcFGWOE?= =?iso-8859-1?Q?xvEcdQp9nEcfyExRTQLDr0bOgLr4qzL2FGQkkXO6TZULW8E0vpX1GKWoJA?= =?iso-8859-1?Q?TOjyNOb5SfKwgCUz67rOEO1tahellK53dkgOn/jNZzZFxufjceN8zDHgcb?= =?iso-8859-1?Q?Ml/WP7OqCnE3wcU9UxJo8UjK1vHGFqf1CSM5SRr/lgLaQFGiLmH2GDO5KP?= =?iso-8859-1?Q?h7r33hnzIzuulhOXootPEA+LW3yVtMF3YN?= X-OriginatorOrg: nxp.com X-MS-Exchange-CrossTenant-Network-Message-Id: 2ea1eeae-cac4-43a4-e880-08dcdcb9da28 X-MS-Exchange-CrossTenant-AuthSource: PAXPR04MB9642.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Sep 2024 16:56:36.7806 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: QTZA4A+ZJss2HDy4kn29dy3calYLuqgqE0Lix6c7Qvwmf29rN3k+szh/M2LSm9cbjitGWv8yQjXQicCRzmo9mA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PAXPR04MB8704 On Tue, Sep 24, 2024 at 01:50:21PM -0300, João Paulo Gonçalves wrote: > Hi Frank, > > On Tue, Sep 24, 2024 at 11:09:51AM -0400, Frank Li wrote: > > On Tue, Sep 24, 2024 at 01:40:53PM +0200, Francesco Dolcini wrote: > > > From: João Paulo Gonçalves > > > > > > Add Toradex Verdin Ivy carrier board support. One notable feature of Ivy > > > is the analog inputs. These inputs are multiplexed, allowing the same > > > input to measure either voltage or current. For current measurements, > > > a GPIO switch enables or disables the shunt resistor. This process is > > > automatically managed by the Linux kernel using the IIO and MUX > > > subsystems. Voltage measurement is always enabled, but the voltage > > > measured by the ADC is scaled by a cascade voltage divider. In the > > > device tree, the equivalent gain of the voltage divider is used, which > > > can be calculated as follows: > > > > > > ------------ > > > + | > > > .-. > > > R1=30K | | > > > | | > > > '-' > > > |------------------- > > > Analog Input (AIN) | | > > > .-. .-. > > > R2=10K | | R3=30K | | > > > | | | | > > > '-' '-' > > > | | > > > | |-------- > > > | .-. + > > > | R4=10K | | > > > | | | ADC Input (Channels 0 and 1) > > > | '-' > > > - | | - > > > -----------| |-------- > > > === === > > > GND GND > > > > > > Vin = Analog Input (AIN) > > > Vout = ADC Input > > > Rth = Thevenin Equiv. Resistance > > > Vth = Thevenin Equiv. Voltage > > > RL = Load Resistor > > > > > > R1 = 30K, R2 = 10K, R3 = 30K, R4 = 10K > > > RL = R4 = 10K > > > > > > Rth = (R1 // R2) + R3 = 37500 Ohms > > > Vth = (Vin * R2) / (R1 + R2) = Vin/4; > > > Vout = (Vth * RL)/ (Rth + RL) = Vth/4.75 = Vin/19 > > > Gain = Vout/Vin = 1/19 > > > > which properties related these value? > > The gain value is used on the "ain1_voltage_unmanaged" node for the full-ohms > and output-ohms properties. Okay, why not define a C macros, which calculate value base on input R 's number. Frank > > Best Regards, > João Paulo Gonçalves