diff --git a/src/blocks/common/logic_compare.js b/src/blocks/common/logic_compare.js
index 257bece..a39298d 100644
--- a/src/blocks/common/logic_compare.js
+++ b/src/blocks/common/logic_compare.js
@@ -7,7 +7,20 @@ export default {
 
   generators: {
     json: (block, generator) => {
-      return '{ "message": "JSON not implemented for logic_compare.js"'
+      const
+        operator = block.getFieldValue('OP'),
+        argument0 = generator.valueToCode(block, 'A', 0),
+        argument1 = generator.valueToCode(block, 'B', 0),
+
+        lines = [
+          `"a": ${argument0}`,
+          `"op": "${operator}"`,
+          `"b": ${argument1}`,
+        ],
+
+        indentedLines = generator.prefixLines(lines.join(',\n'), generator.INDENT)
+
+      return [`{\n${indentedLines}\n}`, 0]
     },
 
     markdown: (block, generator) => {
diff --git a/src/blocks/common/math_number.js b/src/blocks/common/math_number.js
index d85828d..3ede339 100644
--- a/src/blocks/common/math_number.js
+++ b/src/blocks/common/math_number.js
@@ -7,7 +7,7 @@ export default {
 
   generators: {
     json: (block, generator) => {
-      return '{ "message": "JSON not implemented for math_number.js"'
+      return [Number(block.getFieldValue('NUM')), 0]
     },
 
     markdown: (block, generator) => {
diff --git a/src/blocks/custom/feed_selector.js b/src/blocks/custom/feed_selector.js
index 7d18102..513dddf 100644
--- a/src/blocks/custom/feed_selector.js
+++ b/src/blocks/custom/feed_selector.js
@@ -35,7 +35,7 @@ export default {
   generators: {
     json: (block, generator) => {
       const feedKey = block.getFieldValue('FEED_KEY')
-      return [feedKey, 0]
+      return [`{ "feedKey": "${feedKey}" }`, 0]
     },
 
     markdown: (block, generator) => {
diff --git a/src/blocks/custom/trigger_on_change.js b/src/blocks/custom/trigger_on_change.js
index 2d7c742..e0d37fd 100644
--- a/src/blocks/custom/trigger_on_change.js
+++ b/src/blocks/custom/trigger_on_change.js
@@ -34,7 +34,7 @@ export default {
 
         lines = [
           `"trigger": "feed_check",`,
-          `"feedKey": "${feedToCheck}",`,
+          `"check": ${feedToCheck},`,
           `"reactive": ${isReactive}`,
         ],