# How to Selective Switch On 1000 Solenoids

#### amit261287

Joined Dec 19, 2019
4
Anyone Please suggest how to selectively provide a short pulse to a particular solenoid from the array of 1000 No's
My application is to selectively open a particular door from a locker room where 1000's of doors are installed. The user selects the door no. from the screen interface and only that door should open

#### ericgibbs

Joined Jan 29, 2010
19,026
hi amit,
You could consider a 32 * 32 matrix.
What are the limitations on the inter wiring of the system.?
Over what distances are you designing for.?
Solenoid voltage/current.??
E

#### jpanhalt

Joined Jan 18, 2008
11,087
Home Depot and other retailers in the order-online, pick-up at store business model have such lockers that open after reading the bar code on a receipts. The one I have seem is a smaller bank of about 64 (8x8) lockers.

I would look up those resources. Maybe 5 sets of 10x20 would reduce the enormity of wiring, if each locker's door is hardwired. Alternatively, I suspect they have common power to each are controlled either by signals over the power lines or (more likely) one or more common wires for control.

If you used a 3-wire system, the lockers would be wired in parallel and controlled by a 16-bit or larger address. Read about the IOT and all the pre-made stuff for that. You would have almost unlimited expandability.

#### amit261287

Joined Dec 19, 2019
4
hi amit,
You could consider a 32 * 32 matrix.
What are the limitations on the inter wiring of the system.?
Over what distances are you designing for.?
Solenoid voltage/current.??
E
hello ericgibbs,

Could you please suggest a high level architecture to solve the problem.
Solenoid Rating is 12V 1A.
All the Cabinets will be installed in a closed room 10x10m
Main Problem is how to selectively power on a particular solenoid (from 1000 No's) through the main controller.
We can initially design network to control 100No but this should be scalable upto 1000

#### Ya’akov

Joined Jan 27, 2019
9,250
hello ericgibbs,

Could you please suggest a high level architecture to solve the problem.
Solenoid Rating is 12V 1A.
All the Cabinets will be installed in a closed room 10x10m
Main Problem is how to selectively power on a particular solenoid (from 1000 No's) through the main controller.
We can initially design network to control 100No but this should be scalable upto 1000
Without more information the obvious solution is to put them on a network and have each locator lsiten for a cryptographically authenticated signal to unlock if its address is signaled.

Such a system would be limited only by the size of the address space.

Ethernet is the obvious method, but because you would potentially need 1000 ports to do it, wireless might be the best way.

#### amit261287

Joined Dec 19, 2019
4
Without more information the obvious solution is to put them on a network and have each locator lsiten for a cryptographically authenticated signal to unlock if its address is signaled.

Such a system would be limited only by the size of the address space.

Ethernet is the obvious method, but because you would potentially need 1000 ports to do it, wireless might be the best way.
Hello @Yaakov Thanks for your message. You mean we can have a wireless module on each locker and control them through PC. If Yes Please suggest how to do that

#### jpanhalt

Joined Jan 18, 2008
11,087

#### Janis59

Joined Aug 21, 2017
1,856
Mamma mia, thousand!! My career very beginning when for any xerox behaving or operating was public death penalty by kgb and only the method of multiplication in underground resistance movement was typewriting and then wax-rolling copies, I got to steel one electromagnetic typewriter machine. It has a normal mechanic typewriter machine letters but moved by 48 magnets. So my task there was to revive this machine for revolutionist leaflets mass-printing. Need to say I went a most prost way, add each magnet the separate bjt structure and composed the binary code already at TTL level connected to first 8080 core. However, while I did it, the times begin to change thus we got a Brother machine what was more handy and after few years even first MS computer with needle printer so the russian bloodsucker government soon was smoked out of the hole.
Anyway, I believe it is true even nowaday, each magnet must have a separate power output cascade - two or three bjt or one mosfer/igbt, but nowadays the addressing system must come on basis of IP code via http - thats much simpler, especially for large user massive.

#### ericgibbs

Joined Jan 29, 2010
19,026
@jpanhalt @ericgibbs Could you please go through this post and suggest a solution. Please read comment section also for few more suggestions
hi,
They claim:

E

#### Ya’akov

Joined Jan 27, 2019
9,250
Hello @Yaakov Thanks for your message. You mean we can have a wireless module on each locker and control them through PC. If Yes Please suggest how to do that
If I was trying to do this I would first investigate the feasibility of using wireless because of the ease of implementation. I would probably start with the idea of a mesh network using Zigbee, or possibly Bluetooth though more likely the former.

If wireless was problematic, my next route would probably be multi drop RS485 or some other robust, bus topology.

I would use multiple, smaller power supplies for the actuator, and ensure they couldn't be overloaded by limiting the number of simultaneous actuations possible on a shard supply.

I would avoid a star topology because of the added complexity of hubs, and WiFi because of the overhead of unnecessary capabilities, but it is possible that the cheapness of the ESP8266 would overcome that objection.

In any case, I think you have skipped some very important steps in the project process.

You need to do all of: discovery, design, development, and deployment or you will build an unmaintainable and un-extendable mess if it ever works at all.

#### Ya’akov

Joined Jan 27, 2019
9,250
If I was trying to do this I would first investigate the feasibility of using wireless because of the ease of implementation. I would probably start with the idea of a mesh network using Zigbee, or possibly Bluetooth though more likely the former.

If wireless was problematic, my next route would probably be multi drop RS485 or some other robust, bus topology.

I would use multiple, smaller power supplies for the actuator, and ensure they couldn't be overloaded by limiting the number of simultaneous actuations possible on a shard supply.

I would avoid a star topology because of the added complexity of hubs, and WiFi because of the overhead of unnecessary capabilities, but it is possible that the cheapness of the ESP8266 would overcome that objection.

In any case, I think you have skipped some very important steps in the project process.

You need to do all of: discovery, design, development, and deployment or you will build an unmaintainable and un-extendable mess if it ever works at all.
I should add one thing. I would probably NOT make each locker independent but would have controllers that hand some number (e.g.: 8) that are local to that group. This would reduce the cost and overhead but doesn’t affect the basic approach.

#### DNA Robotics

Joined Jun 13, 2014
655
I would use individually addressable Neopixels with a photo-transistor on each one to trigger a MOSFET that would energize a solenoid.

#### Alec_t

Joined Sep 17, 2013
14,389
I would first investigate the feasibility of using wireless because of the ease of implementation
Might not be so easy if the lockers are all metal construction and external components would be vandal-prone.

#### KeepItSimpleStupid

Joined Mar 4, 2014
5,088
One question that I might raise, is "how secure"? Access to wires to the solenoid means almost nothing.

Look at MODBUS which runs under RS485 or Ethernet.
Groups
A MATRIX if only one at a time or one group at a time. Use high and low side drivers.
Automotive solenoid drivers have reporting ability for faults.

There is iButton technology.

I did a few solenoid driver designs for shutters.
1) Slow to open was one design. It was near a 1mm thick, \$800 piece of glass and heavily cycled. 2 min on 2 min off aprox.
PWM based
2) On continuous at a much lower voltage. Linear based. Had a fan already.

See what lock hardware already exists. What happens when the solenoid dies?

Power fail? Fail safe? Fail secure?

See: https://www.assaabloyesh.com/ No affiliation.

#### Ya’akov

Joined Jan 27, 2019
9,250
Might not be so easy if the lockers are all metal construction and external components would be vandal-prone.
Hence the investigation, though if you used controllers for 8, 16, 32 or whatever lockers, you could use external antennas out of reach of vandals. Really this design needs thorough and rigorous process as I mentioned in a later post.