Legal Removal Request This form is for reporting content posted on the AB Electronics UK forums that you believe violates your personal legal rights or applicable local laws for your country. Post: Hi I am currently working on a project that requires to be able to calculate/monitor the RMS AC current and voltages for different circuits for safety monitoring and reporting, which will have threshold sets on the RPi for current usage and voltage levels etc. These circuits may/will have different current loads and are all AC, and some may be using 240VAC while others maybe 48VAC. However I'm not sure how to best acehive what I need it to do with the current hardware and code, due to inaccurate readings and sinewave data capture/sampling issues etc. I have got a few ADC Pi's a few months ago and bought some sensors to test with, the ACS712 for AC current sensing and the LC Technology ZMPT101B Voltage sensor module for AC voltage sensing. I am using the demo_readvoltage.py and demo_acs712_30.py from the github ABELectronics ADCPi python libraries. However after hours of testing, I have found the current sensor on AC seems to be inaccurate and give different readings on each test run of the script, regardless on if the same ampage test current is applied or not, Ie not always on either side of 0V on screen, I've tried another sensor same issue. When testing the AC voltage sensor this seems to be more stable in its sinewave like analog output, always either side of 2.5V. However I have adjusted the on board potentiometer, so this may sorted that, hard too tell based on the output to the screen. I have also noticed the sinewave of both voltage and current sensor modules on screen seem to a bit slow to refresh/capture the sinewave. Is this the os.clear function or a possible sampling speed issue by the ADC Pi, I currently have it set on 18? I have tested the current sensor on DC current to see where the issue may lie, again with the demo code (albeit a slight change to the calc_current function, changed workings out to be 2.5) * 10), however it seems to be near accurate current reading with DC so seems to be just an issue with AC. What I'd like to know is whether these two sensor modules would work as desired with the the ADC Pi on AC supplies and if so how I would go about coding the calculation for the current and voltage based on the sinewave input, and if not what other solutions I could look at implementing to acheive this. Ideally I'd like to keep it with the RPi and ADC Pi' s due the rest of the project incorporating other ABElectronics libraries etc. The other options I can think of that could work if the above doesnt, is RMS to DC converters, however I am not sure how these would work when mesauring AC current, and if it did, the below item doesn't look like it supports much current at all. I can see how it would work for AC voltage but not for current, further to this I am not sure how I would begin to code this to work out a voltage to display on screen. I have found one here but not sure if this would be suitable, if it came to finding one: LTC1966-Converter-Precision-Micropower-Delta-RMS-to-DC-Convert-Module The other only option apart from above I can think of would be to buy an Arduino, or two and connect the analogue inputs to this. The Arduino would then sample the data from the sensor modules and feed the calculated voltage and current readings back to the RPi, or the RPi would poll/request for the calculated voltage and current readings. As Arduino is a new thing to me I'd rather stick with the ADC Pi and Raspberry Pi, due to not knowing how to code in Arduino languages at all, and also how I would set the the Pi and Arduino communcation and analog inputs up properly. Any assistance with this and or how to best go about this would be greatly appreciated, its starting to send me slowly insane. If only it could all be DC for this project, it would be much easier. Sorry about the post length, realised I've gone on a bit. Many Thanks Rhys Select the country where you are claiming legal rights. Albania Algeria American Samoa Andorra Angola Anguilla Antarctica Antigua and Barbuda Argentina Aruba Australia Austria Bahamas Bahrain Bangladesh Barbados Belarus Belgium Belize Benin Bermuda Bhutan Bolivia Bosnia And Herzegovina Botswana Bouvet Island Brazil British Indian Ocean Territory British Virgin Islands Brunei Bulgaria Burkina Faso Burundi Cambodia Cameroon Canada Canary Islands Cape Verde Cayman Islands Central African Republic Chad Channel Islands Chile Christmas Island Cocos (Keeling) Islands Colombia Comoros Congo Cook Islands Costa Rica Croatia Cuba Cyprus Czech Republic Denmark Djibouti Dominica Dominican Republic East Timor Ecuador Egypt El Salvador Equatorial Guinea Estonia Ethiopia Falkland Islands (Malvinas) Faroe Islands Federated States of Micronesia Fiji Finland France French Guiana French Polynesia French Southern Territories Gabon Gambia Georgia Germany Ghana Gibraltar Greece Greenland Grenada Guadeloupe Guam Guatemala Guyana Haiti Heard Island and McDonald Islands Honduras Hong Kong Hungary Iceland India Indonesia Ireland Israel Italy Jamaica Japan Jordan Kazakhstan Kenya Kiribati Kuwait Kyrgyzstan Laos Latvia Lesotho Liechtenstein Lithuania Luxembourg Macau Macedonia Madagascar Malawi Malaysia Maldives Mali Malta Marshall Islands Martinique Mauritania Mauritius Mayotte Mexico Micronesia, Federated States Of Moldova, Republic Of Monaco Mongolia Montenegro Montserrat Morocco Mozambique Myanmar Namibia Nauru Nepal Netherlands Netherlands Antilles New Caledonia New Zealand Nicaragua Niue Norfolk Island Northern Mariana Islands Norway Oman Palau Panama Papua New Guinea Paraguay Peru Philippines Pitcairn Poland Portugal Puerto Rico Qatar Reunion Romania Russia Rwanda Samoa San Marino Sao Tome and Principe Saudi Arabia Serbia Seychelles Singapore Slovakia Slovenia Solomon Islands South Africa South Georgia and the South Sandwich Islands South Korea Spain Sri Lanka St. Helena St. Kitts and Nevis St. Lucia St. Pierre and Miquelon St. Vincent and the Grenadines Suriname Svalbard and Jan Mayen Islands Swaziland Sweden Switzerland Syria Taiwan Tajikistan Tanzania Thailand Togo Tokelau Tonga Trinidad and Tobago Tunisia Turkey Turkmenistan Turks and Caicos Islands Tuvalu U.S. Virgin Islands Uganda Ukraine United Arab Emirates United Kingdom United States United States Minor Outlying Islands Uruguay Uzbekistan Vanuatu Vatican City Venezuela Vietnam Wallis and Futuna Islands Western Sahara Yemen Yugoslavia Zambia What legal issue or problem do you wish to report? Please select Privacy / Erasure under GDPR Defamation Intellectual Property Hate Speech Other Please enter the following information so we can process your report. Contact Name: Contact Email: Details of complaint: Submit Complaint